By default, python-oracledb runs in a 'Thin' mode which connects directly to Oracle Database. This mode does not need Oracle Client libraries. However, some additional functionality is available when python-oracledb uses them. Python-oracledb is said to be in 'Thick' mode when Oracle Client libraries are used. Both modes have comprehensive functionality supporting the Python Database API v2.0 Specification. See :ref:`initialization` for how to enable Thick mode.
The following table summarizes the Oracle Database features supported by python-oracledb Thin and Thick modes, and by cx_Oracle 8.3. For more details see :ref:`driverdiff` and :ref:`compatibility`.
.. list-table-with-summary:: Features Supported by python-oracledb and cx_Oracle 8.3
:header-rows: 1
:class: wy-table-responsive
:align: center
:summary: The first column displays the Oracle feature. The second column indicates whether the feature is supported in the python-oracledb Thin mode. The third column indicates whether the feature is supported in the python-oracledb Thick mode. The fourth column indicates if the feature is supported in cx_Oracle 8.3.
* - Oracle Feature
- python-oracledb Thin Mode
- python-oracledb Thick Mode
- cx_Oracle 8.3
* - Python Database API Support
- Yes - a couple of features are not feasible. Many extensions.
- Yes - a couple of features are not feasible. Many extensions.
- Yes - a couple of features are not feasible. Many extensions.
* - Oracle Client version
- Not applicable
- Release 11.2 and later
- Release 11.2 and later
* - Oracle Database version
- Release 12.1 and later
- Release 9.2 and later depending on Oracle Client library version
- Release 9.2 and later depending on Oracle Client library version
* - Standalone connections (see :ref:`standaloneconnection`)
- Yes - must use keyword arguments
- Yes - must use keyword arguments
- Yes
* - Connection Pooling - Heterogeneous and Homogeneous (see :ref:`Connection pooling <connpooling>`)
- Homogeneous only - must use keyword arguments
- Yes - must use keyword arguments
- Yes
* - Connection Pool Connection Load Balancing (CLB)
- Yes
- Yes
- Yes
* - Connection Pool Runtime Load Balancing (RLB)
- No
- Yes
- Yes
* - Connection Pool draining
- Yes
- Yes
- Yes
* - Connection Pool session state callback (see :ref:`sessioncallback`)
- Yes - Python functions but not PL/SQL functions
- Yes
- Yes
* - Connection pool session tagging (see :ref:`conntagging`)
- No
- Yes
- Yes
* - Password authentication
- Yes
- Yes
- Yes
* - External authentication (see :ref:`extauth`)
- No
- Yes
- Yes
* - Oracle Cloud Infrastructure (OCI) Identity and Access Management (IAM) Tokens (see :ref:`iamauth`)
- Yes
- Yes
- Yes - in connection string with appropriate Oracle Client
* - Open Authorization (OAuth 2.0) (see :ref:`oauth2`)
- Yes
- Yes
- Yes - in connection string with appropriate Oracle Client
* - Kerberos and Radius authentication
- No
- Yes
- Yes
* - Lightweight Directory Access Protocol (LDAP) connections
- No
- Yes
- Yes
* - Proxy connections (see :ref:`proxyauth`)
- Yes
- Yes
- Yes
* - Socket Secure (SOCKS) Proxy connections
- No
- No
- No
* - Connection mode privileges (see :ref:`connection-authorization-modes`)
- Yes
- Yes - only :data:`~oracledb.AUTH_MODE_SYSDBA` is supported
- Yes - only :data:`~oracledb.AUTH_MODE_SYSDBA` is supported
* - Preliminary connections
- No
- Yes
- Yes
* - Set the current schema using an attribute
- Yes
- Yes
- Yes
* - Oracle Cloud Database connectivity (see :ref:`autonomousdb`)
- Yes
- Yes
- Yes
* - Real Application Clusters (RAC)
- Yes
- Yes
- Yes
* - Oracle Sharded Databases (see :ref:`connsharding`)
- No
- Yes - No TIMESTAMP support
- Yes - No TIMESTAMP support
* - Oracle Database Native Network Encryption (NNE) (see :ref:`nne`)
- No
- Yes
- Yes
* - Connection pinging API
- Yes
- Yes
- Yes
* - Oracle Net Services ``tnsnames.ora`` file (see :ref:`optnetfiles`)
- Yes
- Yes
- Yes
* - Oracle Net Services ``sqlnet.ora`` file (see :ref:`optnetfiles`)
- No - many values can be set at connection time
- Yes
- Yes
* - Oracle Client library configuration file ``oraaccess.xml`` (see :ref:`optclientfiles`)
- Not applicable
- Yes
- Yes
* - Easy Connect Plus connection strings
- Yes - mostly supported. Unknown settings are ignored and not passed to Oracle Database.
- Yes
- Yes
* - One-way TLS connections (see :ref:`onewaytls`)
- Yes
- Yes
- Yes
* - Mutual TLS (mTLS) connections (see :ref:`twowaytls`)
- Yes - needs a PEM format wallet (see :ref:`createpem`)
- Yes
- Yes
* - Oracle Database Dedicated Servers, Shared Servers and Database Resident Connection Pooling (DRCP)
- Yes
- Yes
- Yes
* - Oracle Database 23c Implicit Connection Pooling with DRCP and PRCP (see :ref:`implicitconnpool`)
- Yes
- Yes
- No
* - Multitenant Databases
- Yes
- Yes
- Yes
* - CMAN and CMAN-TDM connectivity
- Yes
- Yes
- Yes
* - Password changing (see :meth:`Connection.changepassword()`)
- Yes
- Yes
- Yes
* - Statement break/reset (see :meth:`Connection.cancel()`)
- Yes
- Yes
- Yes
* - Edition Based Redefinition (EBR) (see :ref:`ebr`)
- No - not at connect time. ALTER SESSION can be used.
- Yes
- Yes
* - SQL execution (see :ref:`sqlexecution`)
- Yes - bind and fetch all types except BFILE and JSON
- Yes
- Yes
* - PL/SQL execution (see :ref:`plsqlexecution`)
- Yes for scalar types. Yes for collection types using array interface.
- Yes
- Yes
* - Simple Oracle Document Access (SODA) API (see :ref:`SODA <soda>`)
- No
- Yes
- Yes
* - Bind variables for data binding (see :ref:`bind`)
- Yes
- Yes
- Yes
* - Array DML binding for bulk DML and PL/SQL (see :ref:`batchstmnt`)
- Yes
- Yes
- Yes
* - SQL and PL/SQL type and collections (see :ref:`fetchobjects`)
- Yes
- Yes
- Yes
* - Query column metadata
- Yes
- Yes
- Yes
* - Client character set support (see :ref:`globalization`)
- UTF-8
- UTF-8
- Yes - can use Python encodings. Default in 8.0 is UTF-8
* - Oracle Globalization support
- No - All NLS environment variables are ignored. Use Python globalization support instead
- Yes - NLS environment variables are respected except character set in NLS_LANG
- Yes - NLS environment variables are respected except character set in NLS_LANG
* - Row prefetching on first query execute (see :attr:`prefetchrows`)
- Yes - unless the row contains LOBs or similar types
- Yes - unless the row contains LOBs or similar types
- Yes - unless the row contains LOBs or similar types
* - Array fetching for queries (see :attr:`arraysize`)
- Yes
- Yes
- Yes
* - Statement caching (see :ref:`stmtcache`)
- Yes - new driver also supports dropping from the cache
- Yes - new driver also supports dropping from the cache
- Yes
* - Client Result Caching (CRC) (see :ref:`clientresultcache`)
- No
- Yes
- Yes
* - Continuous Query Notification (CQN) (see :ref:`cqn`)
- No
- Yes
- Yes
* - Advanced Queuing (AQ) (see :ref:`aqusermanual`)
- No
- Yes - must use new API introduced in cx_Oracle 7.2
- Yes
* - Call timeouts (see :attr:`Connection.call_timeout`)
- Yes
- Yes
- Yes
* - Scrollable cursors (see :ref:`scrollablecursors`)
- No
- Yes
- Yes
* - Oracle Database startup and shutdown (see :ref:`startup`)
- No
- Yes
- Yes
* - Transaction management (see :ref:`txnmgmnt`)
- Yes
- Yes
- Yes
* - Events mode for notifications
- No
- Yes
- Yes
* - Fast Application Notification (FAN) (see :ref:`fan`)
- No
- Yes
- Yes
* - In-band notifications
- Yes
- Yes
- Yes
* - Transparent Application Failover (TAF)
- No
- Yes - no callback
- Yes - no callback
* - Transaction Guard (TG) (see :ref:`tg`)
- No
- Yes
- Yes
* - Data Guard (DG) and Active Data Guard (ADG)
- Yes
- Yes
- Yes
* - Application Continuity (AC) and Transparent Application Continuity (TAC) (see :ref:`appcont`)
- No
- Yes
- Yes
* - Concurrent programming with asyncio (see :ref:`asyncio`)
- Yes
- No
- No
* - End-to-end monitoring and tracing attributes (see :ref:`tracingsql`)
- Yes
- Yes
- Yes
* - Automatic Diagnostic Repository (ADR)
- No
- Yes
- Yes
* - Java Debug Wire Protocol for debugging PL/SQL (see :ref:`jdwp`)
- Yes
- Yes
- Yes
* - Two-phase Commit (TPC)
- No
- Yes - improved support. See :ref:`tcp`.
- Yes - limited support
* - REF CURSORs and Nested Cursors
- Yes
- Yes
- Yes
* - Pipelined tables
- Yes
- Yes
- Yes
* - Implicit Result Sets
- Yes
- Yes
- Yes
* - Application Contexts
- No
- Yes
- Yes
* - Persistent and Temporary LOBs
- Yes
- Yes
- Yes
* - LOB length prefetching
- Yes
- Yes
- Yes
* - LOB locator operations such as trim
- Yes
- Yes
- Yes
The following table lists the Oracle Database types that are supported in the python-oracledb driver. See Oracle Database Types and PL/SQL Types. The python-oracledb constant shown is the common one. In some python-oracledb APIs you may use other types, for example when binding numeric values.
.. list-table-with-summary:: Oracle Database Data Types Supported
:header-rows: 1
:class: wy-table-responsive
:align: center
:summary: The first column displays the database data type. The second column displays the python-oracledb constant Name. The third column contains notes. The fourth column shows Python types that can be used.
* - Oracle Database Type
- python-oracledb Constant Name
- Notes
- Supported Python Types
* - VARCHAR2
- :data:`~oracledb.DB_TYPE_VARCHAR`
- No relevant notes
- bytes, str
* - NVARCHAR2
- :data:`~oracledb.DB_TYPE_NVARCHAR`
- No relevant notes
- bytes, str
* - NUMBER, FLOAT
- :data:`~oracledb.DB_TYPE_NUMBER`
- No relevant notes
- bool, int, float, decimal.Decimal
* - DATE
- :data:`~oracledb.DB_TYPE_DATE`
- No relevant notes
- datetime.date, datetime.datetime
* - BOOLEAN (PL/SQL and Oracle Database 23c SQL)
- :data:`~oracledb.DB_TYPE_BOOLEAN`
- No relevant notes
- Any type convertible to bool
* - BINARY_DOUBLE
- :data:`~oracledb.DB_TYPE_BINARY_DOUBLE`
- No relevant notes
- bool, int, float, decimal.Decimal
* - BINARY_FLOAT
- :data:`~oracledb.DB_TYPE_BINARY_FLOAT`
- No relevant notes
- bool, int, float, decimal.Decimal
* - TIMESTAMP
- :data:`~oracledb.DB_TYPE_TIMESTAMP`
- No relevant notes
- datetime.date, datetime.datetime
* - TIMESTAMP WITH TIME ZONE
- :data:`~oracledb.DB_TYPE_TIMESTAMP_TZ`
- No relevant notes
- datetime.date, datetime.datetime
* - TIMESTAMP WITH LOCAL TIME ZONE
- :data:`~oracledb.DB_TYPE_TIMESTAMP_LTZ`
- No relevant notes
- datetime.date, datetime.datetime
* - INTERVAL YEAR TO MONTH
- :data:`~oracledb.DB_TYPE_INTERVAL_YM`
- Not supported in python-oracledb.
- Cannot be set
* - INTERVAL DAY TO SECOND
- :data:`~oracledb.DB_TYPE_INTERVAL_DS`
- No relevant notes
- datetime.timedelta
* - RAW
- :data:`~oracledb.DB_TYPE_RAW`
- No relevant notes
- bytes, str
* - LONG
- :data:`~oracledb.DB_TYPE_LONG`
- No relevant notes
- bytes, str
* - LONG RAW
- :data:`~oracledb.DB_TYPE_LONG_RAW`
- No relevant notes
- bytes, str
* - ROWID
- :data:`~oracledb.DB_TYPE_ROWID`
- No relevant notes
- bytes, str
* - UROWID
- :data:`~oracledb.DB_TYPE_ROWID`, :data:`~oracledb.DB_TYPE_UROWID` (only supported in python-oracledb Thin mode)
- May show :data:`~oracledb.DB_TYPE_UROWID` in metadata. See :ref:`Query Metadata Differences <querymetadatadiff>`.
- bytes, str
* - CHAR
- :data:`~oracledb.DB_TYPE_CHAR`
- No relevant notes
- bytes, str
* - BLOB
- :data:`~oracledb.DB_TYPE_BLOB`
- No relevant notes
- :ref:`oracledb.LOB <lobobj>`, bytes, str
* - CLOB
- :data:`~oracledb.DB_TYPE_CLOB`
- No relevant notes
- :ref:`oracledb.LOB <lobobj>`, bytes, str
* - NCHAR
- :data:`~oracledb.DB_TYPE_NCHAR`
- No relevant notes
- bytes, str
* - NCLOB
- :data:`~oracledb.DB_TYPE_NCLOB`, :data:`~oracledb.DB_TYPE_LONG_NVARCHAR` (if fetching NCLOB as a string)
- No relevant notes
- :ref:`oracledb.LOB <lobobj>`, bytes, str
* - BFILE
- :data:`~oracledb.DB_TYPE_BFILE`
- Not supported in python-oracledb Thin mode.
- Cannot be set
* - JSON
- :data:`~oracledb.DB_TYPE_JSON`
- No relevant notes
- Any type convertible to Oracle JSON
* - REF CURSOR (PL/SQL OR nested cursor)
- :data:`~oracledb.DB_TYPE_CURSOR`
- No relevant notes
- :ref:`oracledb.Cursor <cursorobj>`
* - PLS_INTEGER
- :data:`~oracledb.DB_TYPE_BINARY_INTEGER`
- No relevant notes
- bool, int, float, decimal.Decimal
* - BINARY_INTEGER
- :data:`~oracledb.DB_TYPE_BINARY_INTEGER`
- No relevant notes
- bool, int, float, decimal.Decimal
* - REF
- n/a
- Not supported in python-oracledb Thin mode
- n/a
* - XMLType
- :data:`~oracledb.DB_TYPE_XMLTYPE`
- May need to use ``xmltype.getclobval()`` to fetch in python-oracledb Thick mode. See :ref:`xmldatatype`
- bytes, str
* - User-defined types (object type, VARRAY, records, collections, SDO_*types)
- :data:`~oracledb.DB_TYPE_OBJECT`
- No relevant notes
- OBJECT of specific type
Binding of contiguous PL/SQL Index-by BINARY_INTEGER arrays of string, number, and date are supported in python-oracledb Thin and Thick modes. Use :meth:`Cursor.arrayvar()` to build these arrays.