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Ora2Pg - Oracle to PostgreSQL database schema converter
Ora2Pg is a free tool used to migrate an Oracle database to a PostgreSQL
compatible schema. It connects your Oracle database, scans it
automatically and extracts its structure or data, then generates SQL
scripts that you can load into your PostgreSQL database.
Ora2Pg can be used for anything from reverse engineering Oracle database
to huge enterprise database migration or simply replicating some Oracle
data into a PostgreSQL database. It is really easy to use and doesn't
require any Oracle database knowledge other than providing the
parameters needed to connect to the Oracle database.
Ora2Pg consist of a Perl script (ora2pg) and a Perl module (,
the only thing you have to modify is the configuration file ora2pg.conf
by setting the DSN to the Oracle database and optionally the name of a
schema. Once that's done you just have to set the type of export you
want: TABLE with constraints, VIEW, MVIEW, TABLESPACE, SEQUENCE,
By default Ora2Pg exports to a file that you can load into PostgreSQL
with the psql client, but you can also import directly into a PostgreSQL
database by setting its DSN into the configuration file. With all
configuration options of ora2pg.conf you have full control of what
should be exported and how.
Features included:
- Export full database schema (tables, views, sequences, indexes), with
unique, primary, foreign key and check constraints.
- Export grants/privileges for users and groups.
- Export range/list partitions andi sub partitions.
- Export a table selection (by specifying the table names).
- Export Oracle schema to a PostgreSQL 8.4+ schema.
- Export predefined functions, triggers, procedures, packages and
package bodies.
- Export full data or following a WHERE clause.
- Full support of Oracle BLOB object as PG BYTEA.
- Export Oracle views as PG tables.
- Export Oracle user defined types.
- Provide some basic automatic conversion of PLSQL code to PLPGSQL.
- Works on any platform.
- Export Oracle tables as foreign data wrapper tables.
- Export materialized view.
- Show a detailled report of an Oracle database content.
- Migration cost assessment of an Oracle database.
- Migration difficulty level assessment of an Oracle database.
- Migration cost assessment of PL/SQL code from a file.
- Migration cost assessment of Oracle SQL queries stored in a file.
- Generate XML ktr files to be used with Penthalo Data Integrator (Kettle)
- Export Oracle locator and spatial geometries into PostGis.
- Export DBLINK as Oracle FDW.
- Export SYNONYMS as views.
- Export DIRECTORY as external table or directory for external_file extension.
- Full MySQL export just like Oracle database.
- Dispatch a list of SQL orders over multiple PostgreSQL connections
- Perform a diff between Oracle and PostgreSQL database for test purpose.
Ora2Pg does its best to automatically convert your Oracle database to
PostgreSQL but there's still manual works to do. The Oracle specific
PL/SQL code generated for functions, procedures, packages and triggers
has to be reviewed to match the PostgreSQL syntax. You will find some
useful recommendations on porting Oracle PL/SQL code to PostgreSQL
PL/PGSQL at "Converting from other Databases to PostgreSQL", section:
Oracle (
See for a HTML sample of an Oracle
database migration report.
All Perl modules can always be found at CPAN (
Just type the full name of the module (ex: DBD::Oracle) into the search
input box, it will brings you the page for download.
Releases of Ora2Pg stay at
Under Windows you should install Strawberry Perl
( and the OSes corresponding Oracle clients.
It seems that compiling DBD::Oracle from CPAN on Windows can be a
struggle and there be little documentation on that (mostly outdated and
not working). Installing the free version of ActiveState Perl
( could help as they seems to have
an already packaged DBD::Oracle easy to install.
The Oracle Instant Client or a full Oracle installation must be
installed on the system. You can download the RPM from Oracle download
rpm -ivh oracle-instantclient12.2-basic-
rpm -ivh oracle-instantclient12.2-devel-
rpm -ivh oracle-instantclient12.2-jdbc-
rpm -ivh oracle-instantclient12.2-sqlplus-
or simply download the corresponding ZIP archives from Oracle download
center and install them where you want, for example:
You also need a modern Perl distribution (perl 5.10 and more). To
connect to a database and proceed to his migration you need the DBI Perl
module > 1.614. To migrate an Oracle database you need the DBD::Oracle
Perl modules to be installed. To migrate a MySQL database you need the
DBD::MySQL Perl modules. These modules are used to connect to the
database but they are not mandatory if you want to migrate DDL input
To install DBD::Oracle and have it working you need to have the Oracle
client libraries installed and the ORACLE_HOME environment variable must
be defined.
If you plan to export a MySQL database you need to install the Perl
module DBD::mysql which requires that the mysql client libraries are
On some Perl distribution you may need to install the Time::HiRes Perl
By default Ora2Pg dumps export to flat files, to load them into your
PostgreSQL database you need the PostgreSQL client (psql). If you don't
have it on the host running Ora2Pg you can always transfer these files
to a host with the psql client installed. If you prefer to load export
'on the fly', the perl module DBD::Pg is required.
Ora2Pg allows you to dump all output in a compressed gzip file, to do
that you need the Compress::Zlib Perl module or if you prefer using
bzip2 compression, the program bzip2 must be available in your PATH.
Installing Ora2Pg
Like any other Perl Module Ora2Pg can be installed with the following
tar xjf ora2pg-x.x.tar.bz2
cd ora2pg-x.x/
perl Makefile.PL
make && make install
This will install into your site Perl repository, ora2pg into
/usr/local/bin/ and ora2pg.conf into /etc/ora2pg/.
On Windows(tm) OSes you may use instead:
perl Makefile.PL
dmake && dmake install
This will install scripts and libraries into your Perl site installation
directory and the ora2pg.conf file as well as all documentation files
into C:\ora2pg\
To install ora2pg in a different directory than the default one, simply
use this command:
perl Makefile.PL PREFIX=<your_install_dir>
make && make install
then set PERL5LIB to the path to your installation directory before
using Ora2Pg.
export PERL5LIB=<your_install_dir>
ora2pg -c config/ora2pg.conf -t TABLE -b outdir/
If you want to build the binary package for your preferred Linux
distribution take a look at the packaging/ directory of the source
tarball. There is everything to build RPM, Slackware and Debian
packages. See README file in that directory.
Installing DBD::Oracle
Ora2Pg needs the Perl module DBD::Oracle for connectivity to an Oracle
database from perl DBI. To get DBD::Oracle get it from CPAN a perl
module repository.
After setting ORACLE_HOME and LD_LIBRARY_PATH environment variables as
root user, install DBD::Oracle. Proceed as follow:
export LD_LIBRARY_PATH=/usr/lib/oracle/12.2/client64/lib
export ORACLE_HOME=/usr/lib/oracle/12.2/client64
perl -MCPAN -e 'install DBD::Oracle'
If you are running for the first time it will ask many questions; you
can keep defaults by pressing ENTER key, but you need to give one
appropriate mirror site for CPAN to download the modules. Install
through CPAN manually if the above doesn't work:
#perl -MCPAN -e shell
cpan> get DBD::Oracle
cpan> quit
cd ~/.cpan/build/DBD-Oracle*
export LD_LIBRARY_PATH=/usr/lib/oracle/11.2/client64/lib
export ORACLE_HOME=/usr/lib/oracle/11.2/client64
perl Makefile.PL
make install
Installing DBD::Oracle require that the three Oracle packages:
instant-client, SDK and SQLplus are installed as well as the libaio1
If you are using Instant Client from ZIP archives, the LD_LIBRARY_PATH
and ORACLE_HOME will be the same and must be set to the directory where
you have installed the files. For example:
Ora2Pg configuration can be as simple as choosing the Oracle database to
export and choose the export type. This can be done in a minute.
By reading this documentation you will also be able to:
- Select only certain tables and/or column for export.
- Rename some tables and/or column during export.
- Select data to export following a WHERE clause per table.
- Delay database constraints during data loading.
- Compress exported data to save disk space.
- and much more.
The full control of the Oracle database migration is taken though a
single configuration file named ora2pg.conf. The format of this file
consist in a directive name in upper case followed by tab character and
a value. Comments are lines beginning with a #.
There's no specific order to place the configuration directives, they
are set at the time they are read in the configuration file.
For configuration directives that just take a single value, you can use
them multiple time in the configuration file but only the last
occurrence found in the file will be used. For configuration directives
that allow a list of value, you can use it multiple time, the values
will be appended to the list. If you use the IMPORT directive to load a
custom configuration file, directives defined in this file will be
stores from the place the IMPORT directive is found, so it is better to
put it at the end of the configuration file.
Values set in command line options will override values from the
configuration file.
Ora2Pg usage
First of all be sure that libraries and binaries path include the Oracle
Instant Client installation:
export LD_LIBRARY_PATH=/usr/lib/oracle/11.2/client64/lib
export PATH="/usr/lib/oracle/11.2/client64/bin:$PATH"
By default Ora2Pg will look for /etc/ora2pg/ora2pg.conf configuration
file, if the file exist you can simply execute:
or under Windows(tm) run ora2pg.bat file, located in your perl bin
directory. Windows(tm) users may also find a template configuration file
in C:\ora2pg
If you want to call another configuration file, just give the path as
command line argument:
/usr/local/bin/ora2pg -c /etc/ora2pg/new_ora2pg.conf
Here are all command line parameters available when using ora2pg:
Usage: ora2pg [-dhpqv --estimate_cost --dump_as_html] [--option value]
-a | --allow str : Comma separated list of objects to allow from export.
Can be used with SHOW_COLUMN too.
-b | --basedir dir: Set the default output directory, where files
resulting from exports will be stored.
-c | --conf file : Set an alternate configuration file other than the
default /etc/ora2pg/ora2pg.conf.
-d | --debug : Enable verbose output.
-D | --data_type STR : Allow custom type replacement at command line.
-e | --exclude str: Comma separated list of objects to exclude from export.
Can be used with SHOW_COLUMN too.
-h | --help : Print this short help.
-g | --grant_object type : Extract privilege from the given object type.
See possible values with GRANT_OBJECT configuration.
-i | --input file : File containing Oracle PL/SQL code to convert with
no Oracle database connection initiated.
-j | --jobs num : Number of parallel process to send data to PostgreSQL.
-J | --copies num : Number of parallel connections to extract data from Oracle.
-l | --log file : Set a log file. Default is stdout.
-L | --limit num : Number of tuples extracted from Oracle and stored in
memory before writing, default: 10000.
-m | --mysql : Export a MySQL database instead of an Oracle schema.
-n | --namespace schema : Set the Oracle schema to extract from.
-N | --pg_schema schema : Set PostgreSQL's search_path.
-o | --out file : Set the path to the output file where SQL will
be written. Default: output.sql in running directory.
-p | --plsql : Enable PLSQL to PLPGSQL code conversion.
-P | --parallel num: Number of parallel tables to extract at the same time.
-q | --quiet : Disable progress bar.
-s | --source DSN : Allow to set the Oracle DBI datasource.
-t | --type export: Set the export type. It will override the one
given in the configuration file (TYPE).
-T | --temp_dir DIR: Set a distinct temporary directory when two
or more ora2pg are run in parallel.
-u | --user name : Set the Oracle database connection user.
ORA2PG_USER environment variable can be used instead.
-v | --version : Show Ora2Pg Version and exit.
-w | --password pwd : Set the password of the Oracle database user.
ORA2PG_PASSWD environment variable can be used instead.
--forceowner : Force ora2pg to set tables and sequences owner like in
Oracle database. If the value is set to a username this one
will be used as the objects owner. By default it's the user
used to connect to the Pg database that will be the owner.
--nls_lang code: Set the Oracle NLS_LANG client encoding.
--client_encoding code: Set the PostgreSQL client encoding.
--view_as_table str: Comma separated list of views to export as table.
--estimate_cost : Activate the migration cost evaluation with SHOW_REPORT
--cost_unit_value minutes: Number of minutes for a cost evalution unit.
default: 5 minutes, corresponds to a migration conducted by a
PostgreSQL expert. Set it to 10 if this is your first migration.
--dump_as_html : Force ora2pg to dump report in HTML, used only with
SHOW_REPORT. Default is to dump report as simple text.
--dump_as_csv : As above but force ora2pg to dump report in CSV.
--dump_as_sheet : Report migration assessment with one CSV line per database.
--init_project NAME: Initialise a typical ora2pg project tree. Top directory
will be created under project base dir.
--project_base DIR : Define the base dir for ora2pg project trees. Default
is current directory.
--print_header : Used with --dump_as_sheet to print the CSV header
especially for the first run of ora2pg.
--human_days_limit num : Set the number of human-days limit where the migration
assessment level switch from B to C. Default is set to
5 human-days.
--audit_user LIST : Comma separated list of usernames to filter queries in
the DBA_AUDIT_TRAIL table. Used only with SHOW_REPORT
and QUERY export type.
--pg_dsn DSN : Set the datasource to PostgreSQL for direct import.
--pg_user name : Set the PostgreSQL user to use.
--pg_pwd password : Set the PostgreSQL password to use.
--count_rows : Force ora2pg to perform a real row count in TEST action.
--no_header : Do not append Ora2Pg header to output file
--oracle_speed : Use to know at which speed Oracle is able to send
data. No data will be processed or written.
--ora2pg_speed : Use to know at which speed Ora2Pg is able to send
transformed data. Nothing will be written.
See full documentation at for more help or see
manpage with 'man ora2pg'.
ora2pg will return 0 on success, 1 on error. It will return 2 when a
child process has been interrupted and you've gotten the warning
message: "WARNING: an error occurs during data export. Please check
what's happen." Most of the time this is an OOM issue, first try
reducing DATA_LIMIT value.
For developers, it is possible to add your own custom option(s) in the
Perl script ora2pg as any configuration directive from ora2pg.conf can
be passed in lower case to the new Ora2Pg object instance. See ora2pg
code on how to add your own option.
Note that performance might be improved by updating stats on oracle:
Generate a migration template
The two options --project_base and --init_project when used indicate to
ora2pg that he has to create a project template with a work tree, a
configuration file and a script to export all objects from the Oracle
database. Here a sample of the command usage:
ora2pg --project_base /app/migration/ --init_project test_project
Creating project test_project.
Generating generic configuration file
Creating script to automate all exports.
Creating script to automate all imports.
It create a generic config file where you just have to define the Oracle
database connection and a shell script called The
sources/ directory will contains the Oracle code, the schema/ will
contains the code ported to PostgreSQL. The reports/ directory will
contains the html reports with the migration cost assessment.
If you want to use your own default config file, use the -c option to
give the path to that file. Rename it with .dist suffix if you want
ora2pg to apply the generic configuration values otherwise, the
configuration file will be copied untouched.
Once you have set the connection to the Oracle Database you can execute
the script that will export all object type from your
Oracle database and output DDL files into the schema's subdirectories.
At end of the export it will give you the command to export data later
when the import of the schema will be done and verified.
You can choose to load the DDL files generated manually or use the
second script to import those file interactively. If this
kind of migration is not something current for you it's recommended you
to use those scripts.
Oracle database connection
There's 5 configuration directives to control the access to the Oracle
Used to set ORACLE_HOME environment variable to the Oracle libraries
required by the DBD::Oracle Perl module.
This directive is used to set the data source name in the form
standard DBI DSN. For example:;sid=DB_SID;port=1521
for the second notation the SID should be declared in the well known
file $ORACLE_HOME/network/admin/tnsnames.ora or in the path given to
the TNS_ADMIN environment variable.
For MySQL the DSN will lool like this:
the 'sid' part is replaced by 'database'.
These two directives are used to define the user and password for
the Oracle database connection. Note that if you can it is better to
login as Oracle super admin to avoid grants problem during the
database scan and be sure that nothing is missing.
Set this directive to 1 if you connect the Oracle database as simple
user and do not have enough grants to extract things from the
DBA_... tables. It will use tables ALL_... instead.
Warning: if you use export type GRANT, you must set this
configuration option to 0 or it will not works.
This directive may be used if you want to change the default
isolation level of the data export transaction. Default is now to
set the level to a serializable transaction to ensure data
consistency. The allowed values for this directive are:
Releases before 6.2 used to set the isolation level to READ ONLY
transaction but in some case this was breaking data consistency so
now default is set to SERIALIZABLE.
This directive did not control the Oracle database connection or
unless it purely disable the use of any Oracle database by accepting
a file as argument. Set this directive to a file containing PL/SQL
Oracle Code like function, procedure or full package body to prevent
Ora2Pg from connecting to an Oracle database and just apply his
conversion tool to the content of the file. This can be used with
the most of export types: TABLE, TRIGGER, PROCEDURE, VIEW, FUNCTION
or PACKAGE, etc.
This directive can be used to send an initial command to Oracle,
just after the connection. For example to unlock a policy before
reading objects or to set some session parameters. This directive
can be used multiple time.
Data encryption with Oracle server
If your Oracle Client config file already includes the encryption
method, then DBD:Oracle uses those settings to encrypt the connection
while you extract the data. For example if you have configured the
Oracle Client config file (sqlnet.or or .sqlnet) with the following
# Configure encryption of connections to Oracle
SQLNET.CRYPTO_SEED = 'should be 10-70 random characters'
Any tool that uses the Oracle client to talk to the database will be
encrypted if you setup session encryption like above.
For example, Perl's DBI uses DBD-Oracle, which uses the Oracle client
for actually handling database communication. If the installation of
Oracle client used by Perl is setup to request encrypted connections,
then your Perl connection to an Oracle database will also be encrypted.
Full details at
Testing connection
Once you have set the Oracle database DSN you can execute ora2pg to see
if it works:
ora2pg -t SHOW_VERSION -c config/ora2pg.conf
will show the Oracle database server version. Take some time here to
test your installation as most problems take place here, the other
configuration steps are more technical.
If the output.sql file has not exported anything other than the Pg
transaction header and footer there's two possible reasons. The perl
script ora2pg dump an ORA-XXX error, that mean that your DSN or login
information are wrong, check the error and your settings and try again.
The perl script says nothing and the output file is empty: the user
lacks permission to extract something from the database. Try to connect
to Oracle as super user or take a look at directive USER_GRANTS above
and at next section, especially the SCHEMA directive.
By default all messageis are sent to the standard output. If you
give a file path to that directive, all output will be appended to
this file.
Oracle schema to export
The Oracle database export can be limited to a specific Schema or
Namespace, this can be mandatory following the database connection user.
This directive is used to set the schema name to use during export.
For example:
will extract objects associated to the APPS schema.
When no schema name is provided and EXPORT_SCHEMA is enabled, Ora2Pg
will export all objects from all schema of the Oracle instance with
their names prefixed with the scham name.
By default the Oracle schema is not exported into the PostgreSQL
database and all objects are created under the default Pg namespace.
If you want to also export this schema and create all objects under
this namespace, set the EXPORT_SCHEMA directive to 1. This will set
the schema search_path at top of export SQL file to the schema name
set in the SCHEMA directive with the default pg_catalog schema. If
you want to change this path, use the directive PG_SCHEMA.
Enable/disable the CREATE SCHEMA SQL order at starting of the output
file. It is enable by default and concern on TABLE export type.
By default Ora2Pg will only export valid PL/SQL code. You can force
Oracle to compile again the invalidated code to get a chance to have
it obtain the valid status and then be able to export it.
Enable this directive to force Oracle to compile schema before
exporting code. When this directive is enabled and SCHEMA is set to
a specific schema name, only invalid objects in this schema will be
recompiled. If SCHEMA is not set then all schema will be recompiled.
To force recompile invalid object in a specific schema, set
COMPILE_SCHEMA to the schema name you want to recompile.
This will ask to Oracle to validate the PL/SQL that could have been
invalidate after a export/import for example. The 'VALID' or
'INVALID' status applies to functions, procedures, packages and user
defined types.
If the above configuration directive is not enough to validate your
PL/SQL code enable this configuration directive to allow export of
all PL/SQL code even if it is marked as invalid. The 'VALID' or
'INVALID' status applies to functions, procedures, packages and user
defined types.
Allow you to defined/force the PostgreSQL schema to use. By default
if you set EXPORT_SCHEMA to 1 the PostgreSQL search_path will be set
to the schema name exported set as value of the SCHEMA directive.
The value can be a comma delimited list of schema name but not when
using TABLE export type because in this case it will generate the
CREATE SCHEMA statement and it doesn't support multiple schema name.
For example, if you set PG_SCHEMA to something like "user_schema,
public", the search path will be set like this:
SET search_path = user_schema, public;
forcing the use of an other schema (here user_schema) than the one
from Oracle schema set in the SCHEMA directive.
You can also set the default search_path for the PostgreSQL user you
are using to connect to the destination database by using:
ALTER ROLE username SET search_path TO user_schema, public;
in this case you don't have to set PG_SCHEMA.
Without explicit schema, Ora2Pg will export all objects that not
belongs to system schema or role:
Following your Oracle installation you may have several other system
role defined. To append these users to the schema exclusion list,
just set the SYSUSERS configuration directive to a comma-separated
list of system user to exclude. For example:
will add users INTERNAL and SYSDBA to the schema exclusion list.
By default the owner of the database objects is the one you're using
to connect to PostgreSQL using the psql command. If you use an other
user (postgres for exemple) you can force Ora2Pg to set the object
owner to be the one used in the Oracle database by setting the
directive to 1, or to a completely different username by setting the
directive value to that username.
Ora2Pg use the function's security privileges set in Oracle and it
is often defined as SECURITY DEFINER. If you want to override those
security privileges for all functions and use SECURITY DEFINER
instead, enable this directive.
When enabled this directive force ora2pg to export all tables,
indexes constraint and indexes using the tablespace name defined in
Oracle database. This works only with tablespace that are not TEMP,
Activating this directive will force Ora2Pg to add WITH (OIDS) when
creating tables or views as tables. Default is same as PostgreSQL,
List of schema to get functions/procedures meta information that are
used in the current schema export. When replacing call to function
with OUT parameters, if a function is declared in an other package
then the function call rewriting can not be done because Ora2Pg only
know about functions declared in the current schema. By setting a
comma separated list of schema as value of this directive, Ora2Pg
will look forward in these packages for all
functions/procedures/packages declaration before proceeding to
current schema export.
Force Ora2Pg to not look for function declaration. Note that this
will prevent Ora2Pg to rewrite function replacement call if needed.
Do not enable it unless looking forward at function breaks other
Export type
The export action is perform following a single configuration directive
'TYPE', some other add more control on what should be really exported.
Here are the different values of the TYPE directive, default is
- TABLE: Extract all tables with indexes, primary keys, unique keys,
foreign keys and check constraints.
- VIEW: Extract only views.
- GRANT: Extract roles converted to Pg groups, users and grants on all
- SEQUENCE: Extract all sequence and their last position.
- TABLESPACE: Extract storage spaces for tables and indexes (Pg >= v8).
- TRIGGER: Extract triggers defined following actions.
- FUNCTION: Extract functions.
- PROCEDURE: Extract procedures.
- PACKAGE: Extract packages and package bodies.
- INSERT: Extract data as INSERT statement.
- COPY: Extract data as COPY statement.
- PARTITION: Extract range and list Oracle partitions with subpartitions.
- TYPE: Extract user defined Oracle type.
- FDW: Export Oracle tables as foreign table for oracle_fdw.
- MVIEW: Export materialized view.
- QUERY: Try to automatically convert Oracle SQL queries.
- KETTLE: Generate XML ktr template files to be used by Kettle.
- DBLINK: Generate oracle foreign data wrapper server to use as dblink.
- SYNONYM: Export Oracle's synonyms as views on other schema's objects.
- DIRECTORY: Export Oracle's directories as external_file extension objects.
- LOAD: Dispatch a list of queries over multiple PostgreSQl connections.
- TEST: perform a diff between Oracle and PostgreSQL database.
- TEST_VIEW: perform a count on both side of rows returned by views
Only one type of export can be perform at the same time so the TYPE
directive must be unique. If you have more than one only the last
found in the file will be registered.
Some export type can not or should not be load directly into the
PostgreSQL database and still require little manual editing. This is
QUERY and PACKAGE export types especially if you have PLSQL code or
Oracle specific SQL in it.
For TABLESPACE you must ensure that file path exist on the system
and for SYNONYM you may ensure that the object's owners and schemas
correspond to the new PostgreSQL database design.
Note that you can chained multiple export by giving to the TYPE
directive a comma-separated list of export type, but in this case
you must not use COPY or INSERT with other export type.
Ora2Pg will convert Oracle partition using table inheritance,
trigger and functions. See document at Pg site:
The TYPE export allow export of user defined Oracle type. If you
don't use the --plsql command line parameter it simply dump Oracle
user type asis else Ora2Pg will try to convert it to PostgreSQL
The KETTLE export type requires that the Oracle and PostgreSQL DNS
are defined.
Since Ora2Pg v8.1 there's three new export types:
SHOW_VERSION : display Oracle version
SHOW_SCHEMA : display the list of schema available in the database.
SHOW_TABLE : display the list of tables available.
SHOW_COLUMN : display the list of tables columns available and the
Ora2PG conversion type from Oracle to PostgreSQL that will be
applied. It will also warn you if there's PostgreSQL reserved
words in Oracle object names.
Here is an example of the SHOW_COLUMN output:
[2] TABLE CURRENT_SCHEMA (1 rows) (Warning: 'CURRENT_SCHEMA' is a reserved word in PostgreSQL)
CONSTRAINT : NUMBER(22) => bigint (Warning: 'CONSTRAINT' is a reserved word in PostgreSQL)
FREEZE : VARCHAR2(25) => varchar(25) (Warning: 'FREEZE' is a reserved word in PostgreSQL)
[6] TABLE LOCATIONS (23 rows)
LOCATION_ID : NUMBER(4) => smallint
STREET_ADDRESS : VARCHAR2(40) => varchar(40)
POSTAL_CODE : VARCHAR2(12) => varchar(12)
CITY : VARCHAR2(30) => varchar(30)
STATE_PROVINCE : VARCHAR2(25) => varchar(25)
COUNTRY_ID : CHAR(2) => char(2)
Those extraction keywords are use to only display the requested
information and exit. This allow you to quickly know on what you are
going to work.
The SHOW_COLUMN allow an other ora2pg command line option: '--allow
relname' or '-a relname' to limit the displayed information to the
given table.
The SHOW_ENCODING export type will display the NLS_LANG and
CLIENT_ENCODING values that Ora2Pg will used and the real encoding
of the Oracle database with the corresponding client encoding that
could be used with PostgreSQL
Since release v8.12, Ora2Pg allow you to export your Oracle Table
definition to be use with the oracle_fdw foreign data wrapper. By
using type FDW your Oracle tables will be exported as follow:
id integer NOT NULL,
text character varying(30),
floating double precision NOT NULL
) SERVER oradb OPTIONS (table 'ORATAB');
Now you can use the table like a regular PostgreSQL table.
See for more information on this
foreign data wrapper.
Release 10 adds a new export type destined to evaluate the content
of the database to migrate, in terms of objects and cost to end the
SHOW_REPORT : show a detailled report of the Oracle database content.
Here is a sample of report:
There also a more advanced report with migration cost. See the
dedicated chapter about Migration Cost Evaluation.
Activate the migration cost evaluation. Must only be used with
Default is disabled. You may want to use the --estimate_cost command
line option instead to activate this functionality. Note that
enabling this directive will force PLSQL_PGSQL activation.
Set the value in minutes of the migration cost evaluation unit.
Default is five minutes per unit. See --cost_unit_value to change
the unit value at command line.
By default when using SHOW_REPORT the migration report is generated
as simple text, enabling this directive will force ora2pg to create
a report in HTML format.
See for a sample report.
Use this directive to redefined the number of human-days limit where
the migration assessment level must switch from B to C. Default is
set to 10 human-days.
This configuration directive adds multiprocess support to COPY,
FUNCTION and PROCEDURE export type, the value is the number of
process to use. Default is multiprocess disable.
This directive is used to set the number of cores to used to
parallelize data import into PostgreSQL. During FUNCTION or
PROCEDURE export type each function will be translated to plpgsql
using a new process, the performances gain can be very important
when you have tons of function to convert.
There's no limitation in parallel processing than the number of
cores and the PostgreSQL I/O performance capabilities.
Doesn't works under Windows Operating System, it is simply disabled.
This configuration directive adds multiprocess support to extract
data from Oracle. The value is the number of process to use to
parallelize the select query. Default is parallel query disable.
The parallelism is built on splitting the query following of the
number of cores given as value to ORACLE_COPIES as follow:
where COLUMN is a technical key like a primary or unique key where
split will be based and the current core used by the query
Doesn't works under Windows Operating System, it is simply disabled.
This directive is used to defined the technical key to used to split
the query between number of cores set with the ORACLE_COPIES
variable. For example:
The parallel query that will be used supposing that -J or
ORACLE_COPIES is set to 8:
where N is the current process forked starting from 0.
This directive is used to defined the number of tables that will be
processed in parallel for data extraction. The limit is the number
of cores on your machine. Ora2Pg will open one database connection
for each parallel table extraction. This directive, when upper than
1, will invalidate ORACLE_COPIES but not JOBS, so the real number of
process that will be used is PARALLEL_TABLES * JOBS.
Note that this directive when set upper that 1 will also
automatically enable the FILE_PER_TABLE directive if your are
exporting to files.
You can force Ora2Pg to use /*+ PARALLEL(tbname, degree) */ hint in
each query used to export data from Oracle by setting a value upper
than 1 to this directive. A value of 0 or 1 disable the use of
parallel hint. Default is disabled.
This directive is used to set the name of the foreign data server
that is used in the "CREATE SERVER name FOREIGN DATA WRAPPER
oracle_fdw ..." command. This name will then be used in the "CREATE
FOREIGN TABLE ..." SQL command. Default is arbitrary set to orcl.
This only concern export type FDW.
This directive, enabled by default, allow to export Oracle's
External Tables as file_fdw foreign tables. To not export these
tables at all, set the directive to 0.
Internal timestamp retrieves from custom type are extracted in the
following format: 01-JAN-77 AM. It is impossible to
know the exact century that must be used, so by default any year
below 49 will be added to 2000 and others to 1900. You can use this
directive to change the default value 49. this is only relevant if
you have user defined type with a column timestamp.
Set the comma separated list of username that must be used to filter
queries from the DBA_AUDIT_TRAIL table. Default is to not scan this
table and to never look for queries. This parameter is used only
with SHOW_REPORT and QUERY export type with no input file for
queries. Note that queries will be normalized before output unlike
when a file is given at input using the -i option or INPUT
Disable this directive if you want to disable check_function_bodies.
SET check_function_bodies = false;
It disables validation of the function body string during CREATE
FUNCTION. Default is to use de postgresql.conf setting that enable
it by default.
Exporting BLOB takes time, you may want to export all data except
the BLOB columns. In this case enable this directive and the BLOB
columns will not be included into data export. That mean that the
BLOB column must not have a NOT NULL constraint.
By default data export order will be done by sorting on table name.
If you have huge tables at end of alphabetic order and you are using
multiprocess, it can be better to set the sort order on size so that
multiple small tables can be processed before the largest tables
finish. In this case set this directive to size. Possible values are
name and size. Note that export type SHOW_TABLE and SHOW_COLUMN will
use this sort order too, not only COPY or INSERT export type.
Limiting objects to export
You may want to export only a part of an Oracle database, here are a set
of configuration directives that will allow you to control what parts of
the database should be exported.
This directive allows you to set a list of objects on witch the
export must be limited, excluding all other objects in the same type
of export. The value is a space or comma-separated list of objects
name to export. You can include valid regex into the list. For
will export objects with name EMPLOYEES, COUNTRIES, all objects
beginning with 'SALE_' and all objects with a name ending by
'_GEOM_SEQ'. The object depends of the export type. Note that regex
will not works with 8i database, you must use the % placeholder
instead, Ora2Pg will use the LIKE operator.
This is the manner to declare global filters that will be used with
the current export type. You can also use extended filters that will
be applied on specific objects or only on their related export type.
For example:
ora2pg -p -c ora2pg.conf -t TRIGGER -a 'TABLE[employees]'
will limit export of trigger to those defined on table employees. If
you want to extract all triggers but not some INSTEAD OF triggers:
ora2pg -c ora2pg.conf -t TRIGGER -e 'VIEW[trg_view_.*]'
Or a more complex form:
ora2pg -p -c ora2pg.conf -t TABLE -a 'TABLE[EMPLOYEES]' \
-e 'INDEX[emp_.*];CKEY[emp_salary_min]'
This command will export the definition of the employee table but
will exclude all index beginning with 'emp_' and the CHECK
constraint called 'emp_salary_min'.
When exporting partition you can exclude some partition tables by
ora2pg -p -c ora2pg.conf -t PARTITION -e 'PARTITION[PART_199.* PART_198.*]'
This will exclude partitioned tables for year 1980 to 1999 from the
export but not the main partition table. The trigger will also be
adapted to exclude those table.
With GRANT export you can use this extended form to exclude some
users from the export or limit the export to some others:
ora2pg -p -c ora2pg.conf -t GRANT -a 'USER1 USER2'
ora2pg -p -c ora2pg.conf -t GRANT -a 'GRANT[USER1 USER2]'
will limit export grants to users USER1 and USER2. But if you don't
want to export grants on some functions for these users, for
ora2pg -p -c ora2pg.conf -t GRANT -a 'USER1 USER2' -e 'FUNCTION[adm_.*];PROCEDURE[adm_.*]'
Advanced filters may need some learning.
Oracle doesn't allow the use of lookahead expression so you may want
to exclude some object that match the ALLOW regexp you have defined.
For example if you want to export all table starting with E but not
those starting with EXP it is not possible to do that in a single
expression. This is why you can start a regular expression with the
! character to exclude object matching the regexp given just after.
Our previous example can be written as follow:
it will be translated into:
REGEXP_LIKE(..., '^E.*$') AND NOT REGEXP_LIKE(..., '^EXP.*$')
in the object search expression.
This directive is the opposite of the previous, it allow you to
define a space or comma-separated list of object name to exclude
from the export. You can include valid regex into the list. For
will exclude object with name EMPLOYEES, COUNTRIES and all tables
beginning with 'tmp_'.
For example, you can ban from export some unwanted function with
this directive:
EXCLUDE write_to_.* send_mail_.*
this example will exclude all functions, procedures or functions in
a package with the name beginning with those regex. Note that regex
will not works with 8i database, you must use the % placeholder
instead, Ora2Pg will use the NOT LIKE operator.
See above (directive 'ALLOW') for the extended syntax.
Set which view to export as table. By default none. Value must be a
list of view name or regexp separated by space or comma. If the
object name is a view and the export type is TABLE, the view will be
exported as a create table statement. If export type is COPY or
INSERT, the corresponding data will be exported.
See chapter "Exporting views as PostgreSQL table" for more details.
When exporting GRANTs you can specify a comma separated list of
objects for which privilege will be exported. Default is export for
all objects. Here are the possibles values TABLE, VIEW, MATERIALIZED
DIRECTORY. Only one object type is allowed at a time. For example
set it to TABLE if you just want to export privilege on tables. You
can use the -g option to overwrite it.
When used this directive prevent the export of users unless it is
set to USER. In this case only users definitions are exported.
This directive allows you to specify a WHERE clause filter when
dumping the contents of tables. Value is constructs as follows:
TABLE_NAME[WHERE_CLAUSE], or if you have only one where clause for
each table just put the where clause as the value. Both are possible
too. Here are some examples:
# Global where clause applying to all tables included in the export
# Apply the where clause only on table TABLE_NAME
# Applies two different clause on tables TABLE_NAME and OTHER_TABLE
# and a generic where clause on DATE_CREATE to all other tables
WHERE TABLE_NAME[ID1='001' OR ID1='002] DATE_CREATE > '2001-01-01' OTHER_TABLE[NAME='test']
Any where clause not included into a table name bracket clause will
be applied to all exported table including the tables defined in the
where clause. These WHERE clauses are very useful if you want to
archive some data or at the opposite only export some recent data.
To be able to quickly test data import it is useful to limit data
export to the first thousand tuples of each table. For Oracle define
the following clause:
and for MySQL, use the following:
WHERE 1=1 LIMIT 1,1000
This can also be restricted to some tables data export.
This directive is used to limit the number of item shown in the top
N lists like the top list of tables per number of rows and the top
list of largest tables in megabytes. By default it is set to 10
Enable this directive if you want to continue direct data import on
error. When Ora2Pg received an error in the COPY or INSERT statement
from PostgreSQL it will log the statement to a file called
TABLENAME_error.log in the output directory and continue to next
bulk of data. Like this you can try to fix the statement and
manually reload the error log file. Default is disabled: abort
import on error.
Sometime you may want to extract data from an Oracle table but you
need a a custom query for that. Not just a "SELECT * FROM table"
like Ora2Pg do but a more complex query. This directive allows you
to overwrite the query used by Ora2Pg to extract data. The format is
TABLENAME[SQL_QUERY]. If you have multiple table to extract by
replacing the Ora2Pg query, you can define multiple REPLACE_QUERY
REPLACE_QUERY EMPLOYEES[SELECT,e.fisrtname,lastname FROM EMPLOYEES e JOIN EMP_UPDT u ON ( AND u.cdate>'2014-08-01 00:00:00')]
Controm of Full Text Search export
Several directives can be used to control the way Ora2Pg will export the
Oracle's Text search indexes. By default CONTEXT indexes will be
exported to PostgreSQL FTS indexes but CTXCAT indexes wikk be exported
as indexes using the pg_trgm extension.
Force Ora2Pg to translate Oracle Text indexes into PostgreSQL
indexes using pg_trgm extension. Default is to translate CONTEXT
indexes into FTS indexes and CTXCAT indexes using pg_trgm. Most of
the time using pg_trgm is enough, this is why this directive stand
for. You need to create the pg_trgm extension into the destination
database before importing the objects:
By default Ora2Pg creates a function-based index to translate Oracle
Text indexes.
CREATE INDEX ON t_document
USING gin(to_tsvector('pg_catalog.french', title));
You will have to rewrite the CONTAIN() clause using to_tsvector(),
SELECT id,title FROM t_document
WHERE to_tsvector(title)) @@ to_tsquery('search_word');
To force Ora2Pg to create an extra tsvector column with a dedicated
triggers for FTS indexes, disable this directive. In this case,
Ora2Pg will add the column as follow: ALTER TABLE t_document ADD
COLUMN tsv_title tsvector; Then update the column to compute FTS
vectors if data have been loaded before UPDATE t_document SET
tsv_title = to_tsvector('pg_catalog.french', coalesce(title,'')); To
automatically update the column when a modification in the title
column appears, Ora2Pg adds the following trigger:
CREATE FUNCTION tsv_t_document_title() RETURNS trigger AS $$
IF TG_OP = 'INSERT' OR new.title != old.title THEN
new.tsv_title :=
to_tsvector('pg_catalog.french', coalesce(new.title,''));
return new;
$$ LANGUAGE plpgsql;
ON t_document
FOR EACH ROW EXECUTE PROCEDURE tsv_t_document_title();
When the Oracle text index is defined over multiple column, Ora2Pg
will use setweight() to set a weight in the order of the column
Use this directive to force text search configuration to use. When
it is not set, Ora2Pg will autodetect the stemmer used by Oracle for
each index and pg_catalog.english if the information is not found.
If you want to perform your text search in an accent insensitive
way, enable this directive. Ora2Pg will create an helper function
over unaccent() and creates the pg_trgm indexes using this function.
With FTS Ora2Pg will redefine your text search configuration, for
ALTER MAPPING FOR hword, hword_part, word WITH unaccent, french_stem;
then set the FTS_CONFIG ora2pg.conf directive to fr instead of
When enabled, Ora2pg will create the wrapper function:
CREATE OR REPLACE FUNCTION unaccent_immutable(text)
SELECT public.unaccent('public.unaccent', $1);
the indexes are exported as follow:
CREATE INDEX t_document_title_unaccent_trgm_idx ON t_document
USING gin (unaccent_immutable(title) gin_trgm_ops);
In your queries you will need to use the same function in the search
to be able to use the function-based index. Example:
SELECT * FROM t_document
WHERE unaccent_immutable(title) LIKE '%donnees%';
Same as above but call lower() in the unaccent_immutable() function:
CREATE OR REPLACE FUNCTION unaccent_immutable(text)
SELECT lower(public.unaccent('public.unaccent', $1));
Modifying object structure
One of the great usage of Ora2Pg is its flexibility to replicate Oracle
database into PostgreSQL database with a different structure or schema.
There's three configuration directives that allow you to map those
Enable this directive to reordering columns and minimized the
footprint on disc, so that more rows fit on a data page, which is
the most important factor for speed. Default is disabled, that mean
the same order than in Oracle tables definition, that's should be
enough for most usage. This directive is only used with TABLE
This directive allows you to limit the columns to extract for a
given table. The value consist in a space-separated list of table
name with a set of column between parenthesis as follow:
MODIFY_STRUCT NOM_TABLE(nomcol1,nomcol2,...) ...
for example:
MODIFY_STRUCT T_TEST1(id,dossier) T_TEST2(id,fichier)
This will only extract columns 'id' and 'dossier' from table T_TEST1
and columns 'id' and 'fichier' from the T_TEST2 table. This
directive can only be used with TABLE, COPY or INSERT export. With
TABLE export create table DDL will respect the new list of columns
and all indexes or foreign key pointing to or from a column removed
will not be exported.
This directive allows you to remap a list of Oracle table name to a
PostgreSQL table name during export. The value is a list of
space-separated values with the following structure:
Oracle tables ORIG_TBNAME1 and ORIG_TBNAME2 will be respectively
renamed into DEST_TBNAME1 and DEST_TBNAME2
Like table name, the name of the column can be remapped to a
different name using the following syntax:
For example:
REPLACE_COLS T_TEST(dico:dictionary,dossier:folder)
will rename Oracle columns 'dico' and 'dossier' from table T_TEST
into new name 'dictionary' and 'folder'.
If you want to change the type of some Oracle columns into
PostgreSQL boolean during the export you can define here a list of
tables and column separated by space as follow.
The values set in the boolean columns list will be replaced with the
't' and 'f' following the default replacement values and those
additionally set in directive BOOLEAN_VALUES.
Note that if you have modified the table name with REPLACE_TABLES
and/or the column's name, you need to use the name of the original
table and/or column.
You can also give a type and a precision to automatically convert
all fields of that type as a boolean. For example:
will also replace any field of type number(1) or char(1) as a
boolean in all exported tables.
Use this to add additional definition of the possible boolean values
used in Oracle fields. You must set a space-separated list of
TRUE:FALSE values. By default here are the values recognized by
BOOLEAN_VALUES yes:no y:n 1:0 true:false enabled:disabled
Any values defined here will be added to the default list.
When Ora2Pg find a "zero" date: 0000-00-00 00:00:00 it is replaced
by a NULL. This could be a problem if your column is defined with
NOT NULL constraint. If you can not remove the constraint, use this
directive to set an arbitral date that will be used instead. You can
also use -INFINITY if you don't want to use a fake date.
Add the given value as suffix to indexes names. Useful if you have
indexes with same name as tables. For example:
will add _idx at ed of all index name. Not so common but can help.
Enable this directive to rename all indexes using
tablename_columns_names. Could be very useful for database that have
multiple time the same index name or that use the same name than a
table, which is not allowed by PostgreSQL Disabled by default.
Operator classes text_pattern_ops, varchar_pattern_ops, and
bpchar_pattern_ops support B-tree indexes on the corresponding
types. The difference from the default operator classes is that the
values are compared strictly character by character rather than
according to the locale-specific collation rules. This makes these
operator classes suitable for use by queries involving pattern
matching expressions (LIKE or POSIX regular expressions) when the
database does not use the standard "C" locale. If you enable, with
value 1, this will force Ora2Pg to export all indexes defined on
varchar2() and char() columns using those operators. If you set it
to a value greater than 1 it will only change indexes on columns
where the character limit is greater or equal than this value. For
example, set it to 128 to create these kind of indexes on columns of
type varchar2(N) where N >= 128.
Enable this directive if you want that your partition table name
will be exported using the parent table name. Disabled by default.
If you have multiple partitioned table, when exported to PostgreSQL
some partitions could have the same name but different parent
tables. This is not allowed, table name must be unique.
Enable this directive if you want that your subpartition table name
will be exported using the parent partition name. Enabled by
default. If the partition names are a part of the subpartition
names, you should enable this directive.
If you don't want to reproduce the partitioning like in Oracle and
want to export all partitioned Oracle data into the main single
table in PostgreSQL enable this directive. Ora2Pg will export all
data into the main table name. Default is to use partitioning,
Ora2Pg will export data from each partition and import them into the
PostgreSQL dedicated partition table.
By default Ora2Pg export Oracle tables with the NOLOGGING attribute
as UNLOGGED tables. You may want to fully disable this feature
because you will lost all data from unlogged table in case of
PostgreSQL crash. Set it to 1 to export all tables as normal table.
Oracle Spatial to PostGis
Ora2Pg fully export Spatial object from Oracle database. There's some
configuration directives that could be used to control the export.
By default Ora2Pg is looking at indexes to see the spatial
constraint type and dimensions defined under Oracle. Those
constraints are passed as at index creation using for example:
PARAMETERS('sdo_indx_dims=2, layer_gtype=point');
If those Oracle constraints parameters are not set, the default is
to export those columns as generic type GEOMETRY to be able to
receive any spatial type.
The AUTODETECT_SPATIAL_TYPE directive allows to force Ora2Pg to
autodetect the real spatial type and dimension used in a spatial
column otherwise a non- constrained "geometry" type is used.
Enabling this feature will force Ora2Pg to scan a sample of 50000
column to look at the GTYPE used. You can increase or reduce the
sample size by setting the value of AUTODETECT_SPATIAL_TYPE to the
desired number of line to scan. The directive is enabled by default.
For example, in the case of a column named shape and defined with
Oracle type SDO_GEOMETRY, with AUTODETECT_SPATIAL_TYPE disabled it
will be converted as:
shape geometry(GEOMETRY) or shape geometry(GEOMETRYZ, 4326)
and if the directive is enabled and the column just contains a
single geometry type that use a single dimension:
shape geometry(POLYGON, 4326) or shape geometry(POLYGONZ, 4326)
with a two or three dimensional polygon.
This directive allows you to control the automatically conversion of
Oracle SRID to standard EPSG. If enabled, Ora2Pg will use the Oracle
function sdo_cs.map_oracle_srid_to_epsg() to convert all SRID.
Enabled by default.
If the SDO_SRID returned by Oracle is NULL, it will be replaced by
the default value 8307 converted to its EPSG value: 4326 (see
If the value is upper than 1, all SRID will be forced to this value,
in this case DEFAULT_SRID will not be used when Oracle returns a
null value and the value will be forced to CONVERT_SRID.
Note that it is also possible to set the EPSG value on Oracle side
when sdo_cs.map_oracle_srid_to_epsg() return NULL if your want to
force the value:
system@db> UPDATE sdo_coord_ref_sys SET legacy_code=41014 WHERE srid = 27572;
Use this directive to override the default EPSG SRID to used: 4326.
Can be overwritten by CONVERT_SRID, see above.
This directive can take three values: WKT (default), WKB and
INTERNAL. When it is set to WKT, Ora2Pg will use
SDO_UTIL.TO_WKTGEOMETRY() to extract the geometry data. When it is
set to WKB, Ora2Pg will use the binary output using
SDO_UTIL.TO_WKBGEOMETRY(). If those two extract type are calls at
Oracle side, they are slow and you can easily reach Out Of Memory
when you have lot of rows. Also WKB is not able to export 3D
geometry and some geometries like CURVEPOLYGON. In this case you may
use the INTERNAL extraction type. It will use a Pure Perl library to
convert the SDO_GEOMETRY data into a WKT representation, the
translation is done on Ora2Pg side. This is a work in progress,
please validate your exported data geometries before use. Default
spatial object extraction type is INTERNAL.
Use this directive to add a specific schema to the search path to
look for PostGis functions.
PostgreSQL Import
By default conversion to PostgreSQL format is written to file
'output.sql'. The command:
psql mydb < output.sql
will import content of file output.sql into PostgreSQL mydb database.
When you are performing INSERT/COPY export Ora2Pg proceed by chunks
of DATA_LIMIT tuples for speed improvement. Tuples are stored in
memory before being written to disk, so if you want speed and have
enough system resources you can grow this limit to an upper value
for example: 100000 or 1000000. Before release 7.0 a value of 0 mean
no limit so that all tuples are stored in memory before being
flushed to disk. In 7.x branch this has been remove and chunk will
be set to the default: 10000
When Ora2Pg detect a table with some BLOB it will automatically
reduce the value of this directive by dividing it by 10 until his
value is below 1000. You can control this value by setting
BLOB_LIMIT. Exporting BLOB use lot of resources, setting it to a too
high value can produce OOM.
The Ora2Pg output filename can be changed with this directive.
Default value is output.sql. if you set the file name with extension
.gz or .bz2 the output will be automatically compressed. This
require that the Compress::Zlib Perl module is installed if the
filename extension is .gz and that the bzip2 system command is
installed for the .bz2 extension.
Since release 7.0, you can define a base directory where the file
will be written. The directory must exists.
This directive allows you to specify the full path to the bzip2
program if it can not be found in the PATH environment variable.
Allow object constraints to be saved in a separate file during
schema export. The file will be named CONSTRAINTS_OUTPUT, where
OUTPUT is the value of the corresponding configuration directive.
You can use .gz xor .bz2 extension to enable compression. Default is
to save all data in the OUTPUT file. This directive is usable only
with TABLE export type.
The constraints can be imported quickly into PostgreSQL using the
LOAD export type to parallelize their creation over multiple (-j or
JOBS) connections.
Allow indexes to be saved in a separate file during schema export.
The file will be named INDEXES_OUTPUT, where OUTPUT is the value of
the corresponding configuration directive. You can use .gz xor .bz2
file extension to enable compression. Default is to save all data in
the OUTPUT file. This directive is usable only with TABLE AND
TABLESPACE export type. With the TABLESPACE export, it is used to
write "ALTER INDEX ... TABLESPACE ..." into a separate file named
TBSP_INDEXES_OUPUT that can be loaded at end of the migration after
the indexes creation to move the indexes.
The indexes can be imported quickly into PostgreSQL using the LOAD
export type to parallelize their creation over multiple (-j or JOBS)
Allow foreign key declaration to be saved in a separate file during
schema export. By default foreign keys are exported into the main
output file or in the CONSTRAINT_output.sql file. When enabled
foreign keys will be exported into a file named FKEYS_output.sql
Allow data export to be saved in one file per table/view. The files
will be named as tablename_OUTPUT, where OUTPUT is the value of the
corresponding configuration directive. You can still use .gz xor
.bz2 extension in the OUTPUT directive to enable compression.
Default 0 will save all data in one file, set it to 1 to enable this
feature. This is usable only during INSERT or COPY export type.
Allow functions, procedures and triggers to be saved in one file per
object. The files will be named as objectname_OUTPUT. Where OUTPUT
is the value of the corresponding configuration directive. You can
still use .gz xor .bz2 extension in the OUTPUT directive to enable
compression. Default 0 will save all in one single file, set it to 1
to enable this feature. This is usable only during the corresponding
export type, the package body export has a special behavior.
When export type is PACKAGE and you've enabled this directive,
Ora2Pg will create a directory per package, named with the lower
case name of the package, and will create one file per
function/procedure into that directory. If the configuration
directive is not enabled, it will create one file per package as
packagename_OUTPUT, where OUTPUT is the value of the corresponding
If this directive is set to 1, a TRUNCATE TABLE instruction will be
add before loading data. This is usable only during INSERT or COPY
export type.
When activated, the instruction will be added only if there's no
global DELETE clause or not one specific to the current table (see
Support for include a DELETE FROM ... WHERE clause filter before
importing data and perform a delete of some lines instead of
truncatinf tables. Value is construct as follow:
TABLE_NAME[DELETE_WHERE_CLAUSE], or if you have only one where
clause for all tables just put the delete clause as single value.
Both are possible too. Here are some examples:
DELETE 1=1 # Apply to all tables and delete all tuples
DELETE TABLE_TEST[ID1='001'] # Apply only on table TABLE_TEST
DELETE TABLE_TEST[ID1='001' OR ID1='002] DATE_CREATE > '2001-01-01' TABLE_INFO[NAME='test']
The last applies two different delete where clause on tables
TABLE_TEST and TABLE_INFO and a generic delete where clause on
DATE_CREATE to all other tables. If TRUNCATE_TABLE is enabled it
will be applied to all tables not covered by the DELETE definition.
These DELETE clauses might be useful with regular "updates".
Set this parameter to 0 to not include the call to \set
ON_ERROR_STOP ON in all SQL scripts generated by Ora2Pg. By default
this order is always present so that the script will immediately
abort when an error is encountered.
Enable this directive to use COPY FREEZE instead of a simple COPY to
export data with rows already frozen. This is intended as a
performance option for initial data loading. Rows will be frozen
only if the table being loaded has been created or truncated in the
current sub-transaction. This will only works with export to file
and when -J or ORACLE_COPIES is not set or default to 1. It can be
used with direct import into PostgreSQL under the same condition but
-j or JOBS must also be unset or default to 1.
By default Ora2Pg use CREATE OR REPLACE in function DDL, if you need
not to override existing functions disable this configuration
directive, DDL will not include OR REPLACE.
Enabling this directive will prevent Ora2Pg to print his header into
output files. Only the translated code will be written.
When using Ora2Pg export type INSERT or COPY to dump data to file and
that FILE_PER_TABLE is enabled, you will be warned that Ora2Pg will not
export data again if the file already exists. This is to prevent
downloading twice table with huge amount of data. To force the download
of data from these tables you have to remove the existing output file
If you want to import data on the fly to the PostgreSQL database you
have three configuration directives to set the PostgreSQL database
connection. This is only possible with COPY or INSERT export type as for
database schema there's no real interest to do that.
Use this directive to set the PostgreSQL data source namespace using
DBD::Pg Perl module as follow:
will connect to database 'pgdb' on localhost at tcp port 5432.
These two directives are used to set the login user and password.
Specifies whether transaction commit will wait for WAL records to be
written to disk before the command returns a "success" indication to
the client. This is the equivalent to set synchronous_commit
directive of postgresql.conf file. This is only used when you load
data directly to PostgreSQL, the default is off to disable
synchronous commit to gain speed at writing data. Some modified
version of PostgreSQL, like greenplum, do not have this setting, so
in this set this directive to 1, ora2pg will not try to change the
This directive can be used to send an initial command to PostgreSQL,
just after the connection. For example to set some session
parameters. This directive can be used multiple time.
Column tytpe control
If set to 1 replace portable numeric type into PostgreSQL internal
type. Oracle data type NUMBER(p,s) is approximatively converted to
real and float PostgreSQL data type. If you have monetary fields or
don't want rounding issues with the extra decimals you should
preserve the same numeric(p,s) PostgreSQL data type. Do that only if
you need very good precision because using numeric(p,s) is slower
than using real or double.
If set to 1 replace portable numeric type into PostgreSQL internal
type. Oracle data type NUMBER(p) or NUMBER are converted to
smallint, integer or bigint PostgreSQL data type following the
length of the precision. If NUMBER without precision are set to
DEFAULT_NUMERIC (see bellow).
NUMBER without precision are converted by default to bigint only if
PG_INTEGER_TYPE is true. You can overwrite this value to any PG
type, like integer or float.
If you're experiencing any problem in data type schema conversion
with this directive you can take full control of the correspondence
between Oracle and PostgreSQL types to redefine data type
translation used in Ora2pg. The syntax is a comma-separated list of
"Oracle datatype:Postgresql datatype". Here are the default list
DATA_TYPE DATE:timestamp,LONG:text,LONG RAW:bytea,CLOB:text,NCLOB:text,BLOB:bytea,BFILE:bytea,RAW:bytea,UROWID:oid,ROWID:oid,FLOAT:double precision,DEC:decimal,DECIMAL:decimal,DOUBLE PRECISION:double precision,INT:numeric,INTEGER:numeric,REAL:real,SMALLINT:smallint,BINARY_FLOAT:double precision,BINARY_DOUBLE:double precision,TIMESTAMP:timestamp,XMLTYPE:xml,BINARY_INTEGER:integer,PLS_INTEGER:integer,TIMESTAMP WITH TIME ZONE:timestamp with time zone,TIMESTAMP WITH LOCAL TIME ZONE:timestamp with time zone
Note that the directive and the list definition must be a single
If you want to replace a type with a precision and scale you need to
escape the coma with a backslash. For example, if you want to
replace all NUMBER(*,0) into bigint instead of numeric(38) add the
DATA_TYPE NUMBER(*\,0):bigint
You don't have to recopy all default type conversion but just the
one you want to rewrite.
There's a special case with BFILE when they are converted to type
TEXT, they will just contains the full path to the external file. If
you set the destination type to BYTEA, the default, Ora2Pg will
export the content of the BFILE as bytea. The third case is when you
set the destination type to EFILE, in this case, Ora2Pg will export
export type to export the existing directories as well as privileges
on those directories.
There's no SQL function available to retrieve the path to the BFILE.
Ora2Pg have to create one using the DBMS_LOB package.
CREATE OR REPLACE FUNCTION ora2pg_get_bfilename( p_bfile IN BFILE )
l_dir VARCHAR2(4000);
l_fname VARCHAR2(4000);
l_path VARCHAR2(4000);
dbms_lob.FILEGETNAME( p_bfile, l_dir, l_fname );
SELECT directory_path INTO l_path FROM all_directories
WHERE directory_name = l_dir;
l_dir := rtrim(l_path,'/');
RETURN l_dir || '/' || l_fname;
This function is only created if Ora2Pg found a table with a BFILE
column and that the destination type is TEXT. The function is
dropped at the end of the export. This concern both, COPY and INSERT
export type.
There's no SQL function available to retrieve BFILE as an EFILE
record, then Ora2Pg have to create one using the DBMS_LOB package.
CREATE OR REPLACE FUNCTION ora2pg_get_efile( p_bfile IN BFILE )
l_dir VARCHAR2(4000);
l_fname VARCHAR2(4000);
dbms_lob.FILEGETNAME( p_bfile, l_dir, l_fname );
RETURN '(' || l_dir || ',' || l_fnamei || ')';
This function is only created if Ora2Pg found a table with a BFILE
column and that the destination type is EFILE. The function is
dropped at the end of the export. This concern both, COPY and INSERT
export type.
To set the destination type, use the DATA_TYPE configuration
for example.
The EFILE type is a user defined type created by the PostgreSQL
extension external_file that can be found here: This is a port of the BFILE
Oracle type to PostgreSQL.
There's no SQL function available to retrieve the content of a
BFILE. Ora2Pg have to create one using the DBMS_LOB package.
filecontent BLOB := NULL;
src_file BFILE := NULL;
l_step PLS_INTEGER := 12000;
l_dir VARCHAR2(4000);
l_fname VARCHAR2(4000);
offset NUMBER := 1;
DBMS_LOB.FILEGETNAME( p_bfile, l_dir, l_fname );
src_file := BFILENAME( l_dir, l_fname );
IF src_file IS NULL THEN
DBMS_LOB.CREATETEMPORARY(filecontent, true);
DBMS_LOB.LOADBLOBFROMFILE (filecontent, src_file, DBMS_LOB.LOBMAXSIZE, offset, offset);
RETURN filecontent;
This function is only created if Ora2Pg found a table with a BFILE
column and that the destination type is bytea (the default). The
function is dropped at the end of the export. This concern both,
COPY and INSERT export type.
About the ROWID and UROWID, they are converted into OID by "logical"
default but this will through an error at data import. There is no
equivalent data type so you might want to use the DATA_TYPE
directive to change the corresponding type in PostgreSQL. You should
consider replacing this data type by a bigserial (autoincremented
sequence), text or uuid data type.
Some time you need to force the destination type, for example a
column exported as timestamp by Ora2Pg can be forced into type date.
Value is a comma-separated list of TABLE:COLUMN:TYPE structure. If
you need to use comma or space inside type definition you will have
to backslash them.
MODIFY_TYPE TABLE1:COL3:varchar,TABLE1:COL4:decimal(9\,6)
Type of table1.col3 will be replaced by a varchar and table1.col4 by
a decimal with precision.
If the column's type is a user defined type Ora2Pg will autodetect
the composite type and will export its data using ROW(). Some Oracle
user defined types are just array of a native type, in this case you
may want to transform this column in simple array of a PostgreSQL
native type. To do so, just redefine the destination type as wanted
and Ora2Pg will also transform the data as an array. For example,
with the following definition in Oracle:
Address VARCHAR2(20),
City VARCHAR2(20),
Phone VARCHAR2(8),
Members mem_type
custom type "mem_type" is just a string array and can be translated
into the following in PostgreSQL:
name varchar(10),
address varchar(20),
city varchar(20),
phone varchar(8),
members text[]
) ;
To do so, just use the directive as follow:
Ora2Pg will take care to transform all data of this column in the
correct format. Only arrays of characters and numerics types are
Taking export under control
The following other configuration directives interact directly with the
export process and give you fine granularity in database export control.
For TABLE export you may not want to export all schema constraints,
the SKIP configuration directive allows you to specify a
space-separated list of constraints that should not be exported.
Possible values are:
- fkeys: turn off foreign key constraints
- pkeys: turn off primary keys
- ukeys: turn off unique column constraints
- indexes: turn off all other index types
- checks: turn off check constraints
For example:
SKIP indexes,checks
will removed indexes ans check constraints from export.
Enable this directive if you want to add primary key definition
inside the create table statement. If disabled (the default) primary
key definition will be add with an alter table statement. Enable it
if you are exporting to GreenPlum PostgreSQL database.
By default names of the primary and unique key in the source Oracle
database are ignored and key names are autogenerated in the target
PostgreSQL database with the PostgreSQL internal default naming
rules. If you want to preserve Oracle primary and unique key names
set this option to 1.
This directive allows you to add an ON UPDATE CASCADE option to a
foreign key when a ON DELETE CASCADE is defined or always. Oracle do
not support this feature, you have to use trigger to operate the ON
UPDATE CASCADE. As PostgreSQL has this feature, you can choose how
to add the foreign key option. There is three value to this
directive: never, the default that mean that foreign keys will be
declared exactly like in Oracle. The second value is delete, that
mean that the ON UPDATE CASCADE option will be added only if the ON
DELETE CASCADE is already defined on the foreign Keys. The last
value, always, will force all foreign keys to be defined using the
update option.
When exporting tables, Ora2Pg normally exports constraints as they
are, if they are non-deferrable they are exported as non-deferrable.
However, non-deferrable constraints will probably cause problems
when attempting to import data to Pg. The FKEY_DEFERRABLE option set
to 1 will cause all foreign key constraints to be exported as
In addition when exporting data the DEFER_FKEY option set to 1 will
add a command to defer all foreign key constraints during data
export and the import will be done in a single transaction. This
will work only if foreign keys have been exported as deferrable and
you are not using direct import to PostgreSQL (PG_DSN is not
defined). Constraints will then be checked at the end of the
This directive can also be enabled if you want to force all foreign
keys to be created as deferrable and initially deferred during
schema export (TABLE export type).
If deferring foreign keys is not possible due to the amount of data
in a single transaction, you've not exported foreign keys as
deferrable or you are using direct import to PostgreSQL, you can use
the DROP_FKEY directive.
It will drop all foreign keys before all data import and recreate
them at the end of the import.
This directive allows you to gain lot of speed improvement during
data import by removing all indexes that are not an automatic index
(indexes of primary keys) and recreate them at the end of data
import. Of course it is far better to not import indexes and
constraints before having imported all data.
This directive is used to disable triggers on all tables in COPY or
INSERT export modes. Available values are USER (disable user-defined
triggers only) and ALL (includes RI system triggers). Default is 0:
do not add SQL statements to disable trigger before data import.
If you want to disable triggers during data migration, set the value
to USER if your are connected as non superuser and ALL if you are
connected as PostgreSQL superuser. A value of 1 is equal to USER.
If set to 1 disables alter of sequences on all tables during COPY or
INSERT export mode. This is used to prevent the update of sequence
during data migration. Default is 0, alter sequences.
By default all data that are not of type date or time are escaped.
If you experience any problem with that you can set it to 1 to
disable character escaping during data export. This directive is
only used during a COPY export. See STANDARD_CONFORMING_STRINGS for
enabling/disabling escape with INSERT statements.
This controls whether ordinary string literals ('...') treat
backslashes literally, as specified in SQL standard. This was the
default before Ora2Pg v8.5 so that all strings was escaped first,
now this is currently on, causing Ora2Pg to use the escape string
syntax (E'...') if this parameter is not set to 0. This is the exact
behavior of the same option in PostgreSQL. This directive is only
used during data export to build INSERT statements. See NOESCAPE for
enabling/disabling escape in COPY statements.
If you want to convert CHAR(n) from Oracle into varchar(n) or text
on PostgreSQL using directive DATA_TYPE, you might want to do some
triming on the data. By default Ora2Pg will auto-detect this
conversion and remove any whitespace at both leading and trailing
position. If you just want to remove the leadings character set the
value to LEADING. If you just want to remove the trailing character,
set the value to TRAILING. Default value is BOTH.
The default trimming character is space, use this directive if you
need to change the character that will be removed. For example, set
it to - if you have leading - in the char(n) field. To use space as
trimming charger, comment this directive, this is the default value.
If you want to preserve the case of Oracle object name set this
directive to 1. By default Ora2Pg will convert all Oracle object
names to lower case. I do not recommend to enable this unless you
will always have to double-quote object names on all your SQL
Allow escaping of column name using Oracle reserved words. Value is
a list of comma-separated reserved word. Default:
Enable this directive if you have table or column names that are a
reserved word for PostgreSQL. Ora2Pg will double quote the name of
the object.
Set this directive to 1 to replace default password by a random
password for all extracted user during a GRANT export.
Since PostgreSQL 9.3, materialized view are supported with the SQL
syntax 'CREATE MATERIALIZED VIEW'. To force Ora2Pg to use the native
PostgreSQL support you must enable this configuration - enable by
default. If you want to use the old style with table and a set of
function, you should disable it.
PostgreSQL version below 9.x do not support IF EXISTS in DDL
statements. Disabling the directive with value 0 will prevent Ora2Pg
to add those keywords in all generated statements. Default value is
1, enabled.
This option is deprecated since Ora2Pg release v7.3.
By default Oracle roles are translated into PostgreSQL groups. If
you have PostgreSQL 8.1 or more consider the use of ROLES and set
this directive to 1 to export roles.
This option is deprecated since Ora2Pg release v7.3.
If set to 0, all IN, OUT or INOUT parameters will not be used into
the generated PostgreSQL function declarations (disable it for
PostgreSQL database version lower than 8.1), This is now enable by
This directive enable or disable the use of default parameter value
in function export. Until PostgreSQL 8.4 such a default value was
not supported, this feature is now enable by default.
Add support to WHEN clause on triggers as PostgreSQL v9.0 now
support it. This directive is enabled by default, set it to 0
disable this feature.
Add support to INSTEAD OF usage on triggers (used with PG >= 9.1),
if this directive is disabled the INSTEAD OF triggers will be
rewritten as Pg rules.
When enabled, export views with CHECK OPTION. Disable it if you have
PostgreSQL version prior to 9.4. Default: 1, enabled.
If disabled, do not export object with IF EXISTS statements. Enabled
by default.
PostgreSQL version prior to 10.0 do not have native partitioning.
Enable this directive if you want to use declarative partitioning.
Enable by default.
Some versions of PostgreSQL like Redshift doesn't support substr()
and it need to be replaced by a call to substring(). In this case,
disable it.
Disable this directive if you are using PG < 9.5, PL/SQL operator
used in named parameter => will be replaced by PostgreSQL
proprietary operator := Enable by default.
Enable this directive if you have PostgreSQL >= 10 to use IDENTITY
columns instead of serial or bigserial data type. If
PG_SUPPORTS_IDENTITY is disabled and there is IDENTITY column in the
Oracle table, they are exported as serial or bigserial columns. When
it is enabled they are exported as IDENTITY columns like:
CREATE TABLE identity_test_tab (
description varchar(30)
) ;
If there is non default sequence options set in Oracle, they will be
appended after the IDENTITY keyword. Additionally in both cases,
Ora2Pg will create a file AUTOINCREMENT_output.sql with a embedded
function to update the associated sequences with the restart value
set to "SELECT max(colname)+1 FROM tablename". Of course this file
must be imported after data import otherwise sequence will be kept
to start value. Enabled by default.
PostgreSQL v11 adds support of PROCEDURE, enable it if you use such
Use btree_gin extension to create bitmap like index with pg >= 9.4
You will need to create the extension by yourself: create extension
btree_gin; Default is to create GIN index, when disabled, a btree
index will be created
Use pg_background extension to create an autonomous transaction
instead of using a dblink wrapper. With pg >= 9.5 only. Default is
to use dblink. See about
this extension.
By default if you have an autonomous transaction translated using
dblink extension instead of pg_background the connection is defined
using the values set with PG_DSN, PG_USER and PG_PWD. If you want to
fully override the connection string use this directive as follow to
set the connection in the autonomous transaction wrapper function.
For example:
DBLINK_CONN port=5432 dbname=pgdb host=localhost user=pguser password=pgpass
Use this directive to set the database handle's 'LongReadLen'
attribute to a value that will be the larger than the expected size
of the LOBs. The default is 1MB witch may not be enough to extract
BLOBs or CLOBs. If the size of the LOB exceeds the 'LongReadLen'
DBD::Oracle will return a 'ORA-24345: A Truncation' error. Default:
1023*1024 bytes.
Take a look at this page to learn more:
Important note: If you increase the value of this directive take
care that DATA_LIMIT will probably needs to be reduced. Even if you
only have a 1MB blob, trying to read 10000 of them (the default
DATA_LIMIT) all at once will require 10GB of memory. You may extract
data from those table separatly and set a DATA_LIMIT to 500 or
lower, otherwise you may experience some out of memory.
If you want to bypass the 'ORA-24345: A Truncation' error, set this
directive to 1, it will truncate the data extracted to the
LongReadLen value. Disable by default so that you will be warned if
your LongReadLen value is not high enough.
Disable this if you don't want to load full content of BLOB and CLOB
and use LOB locators instead. This is useful to not having to set
LONGREADLEN. Note that this will not improve speed of BLOB export as
most of the time is always consumed by the bytea escaping and in
this case data will be processed line by line and not by chunk of
DATA_LIMIT rows. For more information on how it works, see
ta_Interface_for_LOB_Locators Default is enabled, it will not use
LOB locators for backward compatibility.
Force the use getStringVal() instead of getClobVal() for XML data
export. Default is 1, enabled for backward compatibility. Set it to
0 to use extract method a la CLOB.
Set it to O if you want to disable export of millisecond from Oracle
timestamp columns. By default milliseconds are exported with the use
of following format:
Disabling will force the use of the following Oracle format:
to_char(..., 'YYYY-MM-DD HH24:MI:SS')
By default milliseconds are exported.
Set this to 1 if you don't want to export comment associated to
tables and columns definition. Default is enabled.
Control MySQL export behavior
Enable this if double pipe and double ampersand (|| and &&) should
not be taken as equivalent to OR and AND. It depend of the variable
@sql_mode, Use it only if Ora2Pg fail on auto detecting this
Enable this directive if you want EXTRACT() replacement to use the
internal format returned as an integer, for example DD HH24:MM:SS
will be replaced with format; DDHH24MMSS::bigint, this depend of
your apps usage.
Special options to handle character encoding
By default Ora2Pg will set NLS_LANG to AMERICAN_AMERICA.AL32UTF8 and
NLS_NCHAR to AL32UTF8. It is not recommanded to change those
settings but in some case it could be useful. Using your own
settings with those configuration directive will change the client
encoding at Oracle side by setting the environment variables
By default Ora2Pg will force Perl to use utf8 I/O encoding. This is
done through a call to the Perl pragma:
use open ':utf8';
You can override this encoding by using the BINMODE directive, for
example you can set it to :locale to use your locale or iso-8859-7,
it will respectively use
use open ':locale';
use open ':encoding(iso-8859-7)';
If you have change the NLS_LANG in non UTF8 encoding, you might want
to set this directive. See
for more information. Most of the time, leave this directive
By default PostgreSQL client encoding is automatically set to UTF8
to avoid encoding issue. If you have changed the value of NLS_LANG
you might have to change the encoding of the PostgreSQL client.
You can take a look at the PostgreSQL supported character sets here:
PLSQL to PLPGSQL conversion
Automatic code conversion from Oracle PLSQL to PostgreSQL PLPGSQL is a
work in progress in Ora2Pg and surely you will always have manual work.
The Perl code used for automatic conversion is all stored in a specific
Perl Module named Ora2Pg/ feel free to modify/add you own code
and send me patches. The main work in on function, procedure, package
and package body headers and parameters rewrite.
Enable/disable PLSQL to PLPGSQL conversion. Enabled by default.
Ora2Pg can replace all conditions with a test on NULL by a call to
the coalesce() function to mimic the Oracle behavior where empty
string are considered equal to NULL.
(field1 IS NULL) is replaced by (coalesce(field1::text, '') = '')
(field2 IS NOT NULL) is replaced by (field2 IS NOT NULL AND field2::text <> '')
You might want this replacement to be sure that your application
will have the same behavior but if you have control on you
application a better way is to change it to transform empty string
into NULL because PostgreSQL makes the difference.
Force empty_clob() and empty_blob() to be exported as NULL instead
as empty string for the first one and '\x' for the second. If NULL
is allowed in your column this might improve data export speed if
you have lot of empty lob. Default is to preserve the exact data
from Oracle.
If you don't want to export package as schema but as simple
functions you might also want to replace all call to
package_name.function_name. If you disable the PACKAGE_AS_SCHEMA
directive then Ora2Pg will replace all call to
package_name.function_name() by package_name_function_name().
Default is to use a schema to emulate package.
The replacement will be done in all kind of DDL or code that is
parsed by the PLSQL to PLPGSQL converter. PLSQL_PGSQL must be
enabled or -p used in command line.
Enable this directive if the rewrite of Oracle native syntax (+) of
OUTER JOIN is broken. This will force Ora2Pg to not rewrite such
code, default is to try to rewrite simple form of rigth outer join
for the moment.
By default Ora2Pg will convert call to SYS_GUID() Oracle function
with a call to uuid_generate_v4 from uuid-ossp extension. You can
redefined it to use the gen_random_uuid function from pgcrypto
extension by changing the function name. Default to
Note that when a RAW(n) column has "SYS_GUID()" as default value
Ora2Pg will automatically translate the type of the column into uuid
which might be the right translation in most of the case.
By default Oracle functions are marked as STABLE as they can not
modify data unless when used in PL/SQL with variable assignment or
as conditional expression. You can force Ora2Pg to create these
function as VOLATILE by disabling this configuration directive.
By default call to COMMIT/ROLLBACK are kept untouched by Ora2Pg to
force the user to review the logic of the function. Once it is fixed
in Oracle source code or you want to comment this calls enable the
following directive.
It is common to see SAVEPOINT call inside PL/SQL procedure together
with a ROLLBACK TO savepoint_name. When COMMENT_COMMIT_ROLLBACK is
enabled you may want to also comment SAVEPOINT calls, in this case
enable it.
Ora2Pg replace all string constant during the pl/sql to plpgsql
translation, string constant are all text include between single
quote. If you have some string placeholder used in dynamic call to
queries you can set a list of regexp to be temporary replaced to not
break the parser. For exemple:
STRING_CONSTANT_REGEXP <placeholder value=".*">
The list of regexp must use the semi colon as separator.
If you want to use functions defined in the Orafce library and
prevent Ora2Pg to translate call to these functions, enable this
directive. The Orafce library can be found here:
By default Ora2pg rewrite add_month(), add_year(), date_trunc() and
to_char() functions, but you may prefer to use the orafce version of
these function that do not need any code transformation.
Enable translation of autonomous transactions into a wrapper
function using dblink or pg_background extension. If you don't want
to use this translation and just want the function to be exported as
a normal one without the pragma call, disable this directive.
Materialized view
Since PostgreSQL 9.3, materialized view are supported with the CREATE
MATERIALIZED VIEW syntax, to force Ora2Pg to use the native PostgreSQL
support you must enable the configuration directive PG_SUPPORTS_MVIEW.
In other case Ora2Pg will export all materialized views as "Snapshot
Materialized Views" as explain in this document:
When exporting materialized view Ora2Pg will first add the SQL code to
create the "materialized_views" table:
CREATE TABLE materialized_views (
mview_name text NOT NULL PRIMARY KEY,
view_name text NOT NULL,
iname text,
all materialized views will have an entry in this table. It then adds
the plpgsql code to create tree functions:
create_materialized_view(text, text, text) used to create a materialized view
drop_materialized_view(text) used to delete a materialized view
refresh_full_materialized_view(text) used to refresh a view
then it adds the SQL code to create the view and the materialized view:
CREATE VIEW mviewname_mview AS
SELECT ... FROM ...;
SELECT create_materialized_view('mviewname','mviewname_mview', change with the name of the column to used for the index);
The first argument is the name of the materialized view, the second the
name of the view on which the materialized view is based and the third
is the column name on which the index should be build (aka most od the
time the primary key). This column is not automatically deduced so you
need to replace its name.
As said above Ora2Pg only supports snapshot materialized views so the
table will be entirely refreshed by issuing first a truncate of the
table and then by load again all data from the view:
To drop the materialized view you just have to call the
drop_materialized_view() function with the name of the materialized view
as parameter.
Other configuration directives
Set it to 1 will enable verbose output.
You can define common Ora2Pg configuration directives into a single
file that can be imported into other configuration files with the
IMPORT configuration directive as follow:
IMPORT commonfile.conf
will import all configuration directives defined into
commonfile.conf into the current configuration file.
Exporting views as PostgreSQL tables
You can export any Oracle view as a PostgreSQL table simply by setting
TYPE configuration option to TABLE to have the corresponding create
table statement. Or use type COPY or INSERT to export the corresponding
data. To allow that you have to specify your views in the VIEW_AS_TABLE
configuration option.
Then if Ora2Pg finds the view it will extract its schema (if TYPE=TABLE)
into a PG create table form, then it will extract the data (if TYPE=COPY
or INSERT) following the view schema.
For example, with the following view:
CREATE OR REPLACE VIEW product_prices (category_id, product_count, low_price, high_price) AS
SELECT category_id, COUNT(*) as product_count,
MIN(list_price) as low_price,
MAX(list_price) as high_price
FROM product_information
GROUP BY category_id;
Setting VIEW_AS_TABLE to product_prices and using export type TABLE,
will force Ora2Pg to detect columns returned types and to generate a
create table statement:
CREATE TABLE product_prices (
category_id bigint,
product_count integer,
low_price numeric,
high_price numeric
Data will be loaded following the COPY or INSERT export type and the
view declaration.
You can use the ALLOW and EXCLUDE directive in addition to filter other
objects to export.
Export as Kettle transformation XML files
The KETTLE export type is useful if you want to use Penthalo Data
Integrator (Kettle) to import data to PostgreSQL. With this type of
export Ora2Pg will generate one XML Kettle transformation files (.ktr)
per table and add a line to manually execute the transformation in the
output.sql file. For example:
ora2pg -c ora2pg.conf -t KETTLE -j 12 -a MYTABLE -o
will generate one file called 'HR.MYTABLE.ktr' and add a line to the
output file (
JAVAMAXMEM=4096 ./ -file $KETTLE_TEMPLATE_PATH/HR.MYTABLE.ktr -level Detailed
The -j 12 option will create a template with 12 processes to insert data
into PostgreSQL. It is also possible to specify the number of parallel
queries used to extract data from the Oracle with the -J command line
option as follow:
ora2pg -c ora2pg.conf -t KETTLE -J 4 -j 12 -a EMPLOYEES -o
This is only possible if you have defined the technical key to used to
split the query between cores in the DEFINED_PKEY configuration
directive. For example:
will force the number of Oracle connection copies to 4 and defined the
SQL query as follow in the Kettle XML transformation file:
<sql>SELECT * FROM HR.EMPLOYEES WHERE ABS(MOD(employee_id,${Internal.Step.Unique.Count}))=${Internal.Step.Unique.Number}</sql>
The KETTLE export type requires that the Oracle and PostgreSQL DSN are
defined. You can also activate the TRUNCATE_TABLE directive to force a
truncation of the table before data import.
The KETTLE export type is an original work of Marc Cousin.
Migration cost assessment
Estimating the cost of a migration process from Oracle to PostgreSQL is
not easy. To obtain a good assessment of this migration cost, Ora2Pg
will inspect all database objects, all functions and stored procedures
to detect if there's still some objects and PL/SQL code that can not be
automatically converted by Ora2Pg.
Ora2Pg has a content analysis mode that inspect the Oracle database to
generate a text report on what the Oracle database contains and what can
not be exported.
To activate the "analysis and report" mode, you have to use the export
de type SHOW_REPORT like in the following command:
ora2pg -t SHOW_REPORT
Here is a sample report obtained with this command:
Ora2Pg: Oracle Database Content Report
Version Oracle Database 10g Enterprise Edition Release
Schema HR
Size 880.00 MB
Object Number Invalid Comments
CLUSTER 2 0 Clusters are not supported and will not be exported.
FUNCTION 40 0 Total size of function code: 81992.
INDEX 435 0 232 index(es) are concerned by the export, others are automatically generated and will
do so on PostgreSQL. 1 bitmap index(es). 230 b-tree index(es). 1 reversed b-tree index(es)
Note that bitmap index(es) will be exported as b-tree index(es) if any. Cluster, domain,
bitmap join and IOT indexes will not be exported at all. Reverse indexes are not exported
too, you may use a trigram-based index (see pg_trgm) or a reverse() function based index
and search. You may also use 'varchar_pattern_ops', 'text_pattern_ops' or 'bpchar_pattern_ops'
operators in your indexes to improve search with the LIKE operator respectively into
varchar, text or char columns.
MATERIALIZED VIEW 1 0 All materialized view will be exported as snapshot materialized views, they
are only updated when fully refreshed.
PACKAGE BODY 2 1 Total size of package code: 20700.
PROCEDURE 7 0 Total size of procedure code: 19198.
SEQUENCE 160 0 Sequences are fully supported, but all call to sequence_name.NEXTVAL or sequence_name.CURRVAL
will be transformed into NEXTVAL('sequence_name') or CURRVAL('sequence_name').
TABLE 265 0 1 external table(s) will be exported as standard table. See EXTERNAL_TO_FDW configuration
directive to export as file_fdw foreign tables or use COPY in your code if you just
want to load data from external files. 2 binary columns. 4 unknown types.
TABLE PARTITION 8 0 Partitions are exported using table inheritance and check constraint. 1 HASH partitions.
2 LIST partitions. 6 RANGE partitions. Note that Hash partitions are not supported.
TRIGGER 30 0 Total size of trigger code: 21677.
TYPE 7 1 5 type(s) are concerned by the export, others are not supported. 2 Nested Tables.
2 Object type. 1 Subtype. 1 Type Boby. 1 Type inherited. 1 Varrays. Note that Type
inherited and Subtype are converted as table, type inheritance is not supported.
TYPE BODY 0 3 Export of type with member method are not supported, they will not be exported.
VIEW 7 0 Views are fully supported, but if you have updatable views you will need to use
INSTEAD OF triggers.
DATABASE LINK 1 0 Database links will not be exported. You may try the dblink perl contrib module or use
the SQL/MED PostgreSQL features with the different Foreign Data Wrapper (FDW) extensions.
Note: Invalid code will not be exported unless the EXPORT_INVALID configuration directive is activated.
Once the database can be analysed, Ora2Pg, by his ability to convert SQL
and PL/SQL code from Oracle syntax to PostgreSQL, can go further by
estimating the code difficulties and estimate the time necessary to
operate a full database migration.
To estimate the migration cost in man-days, Ora2Pg allow you to use a
configuration directive called ESTIMATE_COST that you can also enabled
at command line:
This feature can only be used with the SHOW_REPORT, FUNCTION, PROCEDURE,
PACKAGE and QUERY export type.
ora2pg -t SHOW_REPORT --estimate_cost
The generated report is same as above but with a new 'Estimated cost'
column as follow:
Ora2Pg: Oracle Database Content Report
Version Oracle Database 10g Express Edition Release
Schema HR
Size 890.00 MB
Object Number Invalid Estimated cost Comments
DATABASE LINK 3 0 9 Database links will be exported as SQL/MED PostgreSQL's Foreign Data Wrapper (FDW) extensions
using oracle_fdw.
FUNCTION 2 0 7 Total size of function code: 369 bytes. HIGH_SALARY: 2, VALIDATE_SSN: 3.
INDEX 21 0 11 11 index(es) are concerned by the export, others are automatically generated and will do so
on PostgreSQL. 11 b-tree index(es). Note that bitmap index(es) will be exported as b-tree
index(es) if any. Cluster, domain, bitmap join and IOT indexes will not be exported at all.
Reverse indexes are not exported too, you may use a trigram-based index (see pg_trgm) or a
reverse() function based index and search. You may also use 'varchar_pattern_ops', 'text_pattern_ops'
or 'bpchar_pattern_ops' operators in your indexes to improve search with the LIKE operator
respectively into varchar, text or char columns.
JOB 0 0 0 Job are not exported. You may set external cron job with them.
MATERIALIZED VIEW 1 0 3 All materialized view will be exported as snapshot materialized views, they
are only updated when fully refreshed.
PACKAGE BODY 0 2 54 Total size of package code: 2487 bytes. Number of procedures and functions found
inside those packages: 7. two_proc.get_table: 10, emp_mgmt.create_dept: 4,
emp_mgmt.hire: 13, emp_mgmt.increase_comm: 4, emp_mgmt.increase_sal: 4,
emp_mgmt.remove_dept: 3, emp_mgmt.remove_emp: 2.
PROCEDURE 4 0 39 Total size of procedure code: 2436 bytes. TEST_COMMENTAIRE: 2, SECURE_DML: 3,
SEQUENCE 3 0 0 Sequences are fully supported, but all call to sequence_name.NEXTVAL or sequence_name.CURRVAL
will be transformed into NEXTVAL('sequence_name') or CURRVAL('sequence_name').
SYNONYM 3 0 4 SYNONYMs will be exported as views. SYNONYMs do not exists with PostgreSQL but a common workaround
is to use views or set the PostgreSQL search_path in your session to access
object outside the current schema.
user1.emp_details_view_v is an alias to hr.emp_details_view.
user1.emp_table is an alias to hr.employees@other_server.
user1.offices is an alias to hr.locations.
TABLE 17 0 8.5 1 external table(s) will be exported as standard table. See EXTERNAL_TO_FDW configuration
directive to export as file_fdw foreign tables or use COPY in your code if you just want to
load data from external files. 2 binary columns. 4 unknown types.
TRIGGER 1 1 4 Total size of trigger code: 123 bytes. UPDATE_JOB_HISTORY: 2.
TYPE 7 1 5 5 type(s) are concerned by the export, others are not supported. 2 Nested Tables. 2 Object type.
1 Subtype. 1 Type Boby. 1 Type inherited. 1 Varrays. Note that Type inherited and Subtype are
converted as table, type inheritance is not supported.
TYPE BODY 0 3 30 Export of type with member method are not supported, they will not be exported.
VIEW 1 1 1 Views are fully supported, but if you have updatable views you will need to use INSTEAD OF triggers.
Total 65 8 162.5 162.5 cost migration units means approximatively 2 man day(s).
The last line shows the total estimated migration code in man-days
following the number of migration units estimated for each object. This
migration unit represent around five minutes for a PostgreSQL expert. If
this is your first migration you can get it higher with the
configuration directive COST_UNIT_VALUE or the --cost_unit_value command
line option:
ora2pg -t SHOW_REPORT --estimate_cost --cost_unit_value 10
Ora2Pg is also able to give you a migration difficulty level assessment,
here a sample:
Migration level: B-5
Migration levels:
A - Migration that might be run automatically
B - Migration with code rewrite and a human-days cost up to 5 days
C - Migration with code rewrite and a human-days cost above 5 days
Technical levels:
1 = trivial: no stored functions and no triggers
2 = easy: no stored functions but with triggers, no manual rewriting
3 = simple: stored functions and/or triggers, no manual rewriting
4 = manual: no stored functions but with triggers or views with code rewriting
5 = difficult: stored functions and/or triggers with code rewriting
This assessment consist in a letter A or B to specify if the migration
needs manual rewriting or not. And a number from 1 up to 5 to give you a
technical difficulty level. You have an additional option
--human_days_limit to specify the number of human-days limit where the
migration level should be set to C to indicate that it need a huge
amount of work and a full project management with migration support.
Default is 10 human-days. You can use the configuration directive
HUMAN_DAYS_LIMIT to change this default value permanently.
This feature has been developped to help you or your boss to decide
which database to migrate first and the team that must be mobilized to
operate the migration.
Global Oracle and MySQL migraton assessment
Ora2Pg come with a script ora2pg_scanner that can be used when you have
a huge number of instances and schema to scan for migration assessment.
Usage: ora2pg_scanner -l CSVFILE [-o OUTDIR]
-b | --binpath DIR: full path to directory where the ora2pg binary stays.
Might be useful only on Windows OS.
-c | --config FILE: set custom configuration file to use otherwise ora2pg
will use the default: /etc/ora2pg/ora2pg.conf.
-l | --list FILE : CSV file containing a list of databases to scan with
all required information. The first line of the file
can contain the following header that describes the
format that must be used:
-o | --outdir DIR : (optional) by default all reports will be dumped to a
directory named 'output', it will be created automatically.
If you want to change the name of this directory, set the name
at second argument.
-t | --test : just try all connections by retrieving the required schema
or database name. Useful to validate your CSV list file.
Here is a full example of a CSV databases list file:
The CSV field separator must be a comma.
Note that if you want to scan all schemas from an Oracle instance you just
have to leave the schema field empty, Ora2Pg will automatically detect all
available schemas and generate a report for each one. Of course you need to
use a connection user with enough privileges to be able to scan all schemas.
For example:
will generate a report for all schema in the XE instance. Note that in this
case the SCHEMA directive in ora2pg.conf must not be set.
It will generate a CSV file with the assessment result, one line per
schema or database and a detailed HTML report for each database scanned.
Hint: Use the -t | --test option before to test all your connections in
your CSV file.
For Windows users you must use the -b command line option to set the
directory where ora2pg_scanner stays otherwise the ora2pg command calls
will fail.
Migration assessment method
Migration unit scores given to each type of Oracle database object are
defined in the Perl library lib/Ora2Pg/ in the %OBJECT_SCORE
variable definition.
The number of PL/SQL lines associated to a migration unit is also
defined in this file in the $SIZE_SCORE variable value.
The number of migration units associated to each PL/SQL code
difficulties can be found in the same Perl library lib/Ora2Pg/
in the hash %UNCOVERED_SCORE initialization.
This assessment method is a work in progress so I'm expecting feedbacks
on migration experiences to polish the scores/units attributed in those
Improving indexes and constraints creation speed
Using the LOAD export type and a file containing SQL orders to perform,
it is possible to dispatch those orders over multiple PostgreSQL
connections. To be able to use this feature, the PG_DSN, PG_USER and
PG_PWD must be set. Then:
ora2pg -t LOAD -c config/ora2pg.conf -i schema/tables/INDEXES_table.sql -j 4
will dispatch indexes creation over 4 simultaneous PostgreSQL
This will considerably accelerate this part of the migration process
with huge data size.
Exporting LONG RAW
If you still have columns defined as LONG RAW, Ora2Pg will not be able
to export these kind of data. The OCI library fail to export them and
always return the same first record. To be able to export the data you
need to transform the field as BLOB by creating a temporary table before
migrating data. For example, the Oracle table:
Name NULL ? Type
-------------------- -------- ----------------------------
need to be "translated" into a table using BLOB as follow:
CREATE TABLE test_blob (id NUMBER, c1 BLOB);
And then copy the data with the following INSERT query:
INSERT INTO test_blob SELECT id, to_lob(c1) FROM test_longraw;
Then you just have to exclude the original table from the export (see
EXCLUDE directive) and to renamed the new temporary table on the fly
using the REPLACE_TABLES configuration directive.
Global variables
Oracle allow the use of global variables defined in packages. Ora2Pg
will export these variables for PostgreSQL as user defined custom
variables available in a session. Oracle variables assignement are
exported as call to:
PERFORM set_config('pkgname.varname', value, false);
Use of these variables in the code is replaced by:
where global_variables_type is the type of the variable extracted from
the package definition.
If the variable is a constant or have a default value assigned at
declaration, ora2pg will create a file global_variables.conf with the
definition to include in the postgresql.conf file so that their values
will already be set at database connection. Note that the value can
always modified by the user so you can not have exactly a constant.
Converting your queries with Oracle style outer join (+) syntax to ANSI
standard SQL at the Oracle side can save you lot of time for the
migration. You can use TOAD Query Builder can re-write these using the
proper ANSI syntax, see:
There's also an alternative with SQL Developer Data Modeler, see
Toad is also able to rewrite the native Oracle DECODE() syntax into ANSI
standard SQL CASE statement. You can find some slide about this in a
presentation given at PgConf.RU:
Test the migration
The type of action called TEST allow you to check that all objects from
Oracle database have been created under PostgreSQL. Of course PG_DSN
must be set to be able to check PostgreSQL side. Note that this feature
will respect the schema name limitation if EXPORT_SCHEMA and SCHEMA or
PG_SCHEMA are defined.
ora2pg -t TEST -c config/ora2pg.conf > migration_diff.txt
Will create a file containing the report of all object and row count on
both side, Oracle and PostgreSQL, with an error section giving you the
detail of the differences for each kind of object. Here is a sample
Table ptab2 does not exists in PostgreSQL database.
Table departments doesn't have the same number of indexes in Oracle (2) and in PostgreSQL (1).
OK, Oracle and PostgreSQL have the same number of VIEW.
OK, Oracle and PostgreSQL have the same number of MVIEW.
SEQUENCE does not have the same count in Oracle (1) and in PostgreSQL (0).
TYPE does not have the same count in Oracle (1) and in PostgreSQL (0).
OK, Oracle and PostgreSQL have the same number of FDW.
Here we can see that one table, one index, one sequence and one user
defined type have not been imported yet or have encountered an error.
Author / Maintainer
Gilles Darold <gilles AT darold DOT net>
Please report any bugs, patches, help, etc. to <gilles AT darold DOT
Feature request
If you need new features let me know at <gilles AT darold DOT net>. This
help a lot to develop a better/useful tool.
How to contribute ?
Any contribution to build a better tool is welcome, you just have to
send me your ideas, features request or patches and there will be
Copyright (c) 2000-2019 Gilles Darold - All rights reserved.
This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see < >.
I must thanks a lot all the great contributors, see changelog for all
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