postgresql-tableversion

PostgreSQL table versioning extension, recording row modifications and its history. The extension provides APIs for accessing snapshots of a table at certain revisions and the difference generated between any two given revisions. The extension uses a PL/PgSQL trigger based system to record and provide access to the row revisions.

Easy Installation

Install pgxn-client which is hosted on PyPI:

$ sudo easy_install pgxnclient

Then do:

$ sudo pgxn install table_version

or sudo pgxn load -d my_db table_version

(Run pgxn --help for more info)

Installation via apt-get

Add apt repository:

# Enable fetching packages from packagecloud
# production repository:
$ curl -s \
  https://packagecloud.io/install/repositories/linz/prod/script.deb.sh |
  sudo bash

Then install the package (tweak the PGVER line if needed):

$ PGVER=$(basename `pg_config --sharedir`) \
  sudo apt-get install postgresql-${PGVER}-tableversion

Hard Installation

To build it, just do this:

make
make installcheck
make install

If you encounter an error such as:

"Makefile", line 8: Need an operator

You need to use GNU make, which may well be installed on your system as gmake:

gmake
gmake install
gmake installcheck

If you encounter an error such as:

make: pg_config: Command not found

Be sure that you have pg_config installed and in your path. If you used a package management system such as RPM to install PostgreSQL, be sure that the -devel package is also installed. If necessary tell the build process where to find it:

env PG_CONFIG=/path/to/pg_config make && make installcheck && make install

And finally, if all that fails (and if you're on PostgreSQL 8.1 or lower, it likely will), copy the entire distribution directory to the contrib/ subdirectory of the PostgreSQL source tree and try it there without pg_config:

env NO_PGXS=1 make && make installcheck && make install

If you encounter an error such as:

ERROR:  must be owner of database regression

You need to run the test suite using a super user, such as the default "postgres" super user:

make installcheck PGUSER=postgres

Installing the extension in a database

As an extension

Once table_version is installed, you can add it to a database. If you're running PostgreSQL 9.1.0 or greater, it's a simple as connecting to a database as a super user and running:

CREATE EXTENSION table_version;

The extension will install support configuration tables and functions into the table_version schema.

If you're ugrading from an older version of the extension run:

ALTER EXTENSION table_version UPDATE;

If you've upgraded your cluster to PostgreSQL 9.1 and already had table_version installed, you can upgrade it to a properly packaged extension with:

CREATE EXTENSION table_version FROM unpackaged;

As a facility, the table_version-loader script can be used to both create (but not from unpackaged) and upgrade the extension in an existing database. To use it run:

    table_version-loader <dbname>

As a set of scripts

If it is not possible to install table_version as an extension in your database cluster system you can still use it by loading the support scripts in your database. The table_version-loader script can be used to make this easy, just run:

table_version-loader --no-extension <dbname>

Connection information (postgresql hostname, port, username, password) can all be set using standard environment variables PGHOST, PGPORT, PGUSER, PGPASSWORD.

Dependencies

The table_version extension has no dependencies other than PL/PgSQL.

Test

Installation and upgrade tests use Docker containers. See .github/workflows/test.yml for how to test various aspects.

License

This project is under 3-clause BSD License, except where otherwise specified. See the LICENSE file for more details.