pg_partman 4.0.0

This Release
pg_partman 4.0.0
Date
Status
Stable
Latest Testing
pg_partman 0.4.1 —
Other Releases
Abstract
Extension to manage partitioned tables by time or ID
Released By
keithf4
License
The PostgreSQL License
Resources
Special Files
Tags

Extensions

pg_partman 4.0.0
Extension to manage partitioned tables by time or ID

Documentation

migration_to_partman
Migrating An Existing Partition Set to PG Partition Manager
pg_partman_howto
Example Guide On Setting Up Trigger-based Partitioning
README_test
pg_partman Test Suite

README

PGXN version

PG Partition Manager

pg_partman is an extension to create and manage both time-based and serial-based table partition sets. Native partitioning in PostgreSQL 10 is supported as of pg_partman v3.0.1 and much more extensively as of 4.0.0 along with PostgreSQL 11. Note that all the features of trigger-based partitioning are not yet supported in native, but performance in both reads & writes is significantly better.

Child table creation is all managed by the extension itself. For non-native, trigger function maintenance is also handled. For non-native partitioning, tables with existing data can have their data partitioned in easily managed smaller batches. For native partitioning, the creation of a new partitioned parent must be done first and the data migrated over after setup is complete.

Optional retention policy can automatically drop partitions no longer needed for both native and non-native partitioning.

A background worker (BGW) process is included to automatically run partition maintenance without the need of an external scheduler (cron, etc) in most cases.

All bug reports, feature requests and general questions can be directed to the Issues section on Github. Please feel free to post here no matter how minor you may feel your issue or question may be. - https://github.com/pgpartman/pg_partman/issues

If you're looking for a partitioning system that handles any range type beyond just time & serial, the new native partitioning features in PostgreSQL 10+ are likely the best method for the foreseeable future. If this is something critical to your environment, start planning your upgrades now!

If you're still trying to evaluate whether partitioning is a good choice for your environment, keep an eye on the HypoPG project. Version 2 will have a hypothetical partitioning feature that will let you evaluate different partitioning schemes without requiring you to actually partition your data. I may see about integrating this feature into pg_partman once it is available. - https://hypopg.readthedocs.io

INSTALLATION

Requirement: PostgreSQL >= 9.4

Recommended: pg_jobmon (>=v1.3.2). PG Job Monitor will automatically be used if it is installed and setup properly. https://github.com/omniti-labs/pg_jobmon

In the directory where you downloaded pg_partman, run

make install

If you do not want the background worker compiled and just want the plain PL/PGSQL functions, you can run this instead:

make NO_BGW=1 install

The background worker must be loaded on database start by adding the library to shared_preload_libraries in postgresql.conf

shared_preload_libraries = 'pg_partman_bgw'     # (change requires restart)

You can also set other control variables for the BGW in postgresql.conf. "dbname" is required at a minimum for maintenance to run on the given database(s). These can be added/changed at anytime with a simple reload. See the documentation for more details. An example with some of them:

pg_partman_bgw.interval = 3600
pg_partman_bgw.role = 'keith'
pg_partman_bgw.dbname = 'keith'

Log into PostgreSQL and run the following commands. Schema is optional (but recommended) and can be whatever you wish, but it cannot be changed after installation. If you're using the BGW, the database cluster can be safely started without having the extension first created in the configured database(s). You can create the extension at any time and the BGW will automatically pick up that it exists without restarting the cluster (as long as shared_preload_libraries was set) and begin running maintenance as configured.

CREATE SCHEMA partman;
CREATE EXTENSION pg_partman SCHEMA partman;

As of version 4.0.0, the privileges required to run pg_partman have been reduced greatly. Superuser is still required to install pg_partman and a superuser must still own the extension objects for things to fully run. But the functions with SECURITY DEFINER (ie, run as a superuser) are very minimal, and in a future update, will be completely optional. It is recommended that a dedicated role is created for running pg_partman functions and to be the owner of all partition sets that pg_partman maintains. At a minimum this role will need the following privileges (assuming pg_partman is installed to the "partman" schema):

CREATE ROLE partman WITH LOGIN;
GRANT ALL ON ALL TABLES IN SCHEMA partman TO partman;
GRANT EXECUTE ON ALL FUNCTIONS IN SCHEMA partman TO partman;
GRANT EXECUTE ON ALL PROCEDURES IN SCHEMA partman TO partman;  -- PG11+ only
GRANT ALL ON SCHEMA my_partition_schema TO partman;

If you need the role to also be able to create schemas, you will need to grant create on the database as well. In general this shouldn't be required as long as you give the above role CREATE privileges on any pre-existing schemas that will contain partition sets.

GRANT CREATE ON DATABASE mydb TO partman;

I've received many requests for being able to install this extension on Amazon RDS. RDS does not support third-party extension management outside of the ones it has approved and provides itself. Therefore, I cannot provide support for running this extension in RDS if the limitations are RDS related. If you'd like to see this extension available there, please send an email to rds-postgres-extensions-request@amazon.com requesting that they include it. The more people that do so, the more likely it will happen!

UPGRADE

Run "make install" same as above to put the script files and libraries in place. Then run the following in PostgreSQL itself:

ALTER EXTENSION pg_partman UPDATE TO '<latest version>';

If you are doing a pg_dump/restore and you've upgraded pg_partman in place from previous versions, it is recommended you use the --column-inserts option when dumping and/or restoring pg_partman's configuration tables. This is due to ordering of the configuration columns possibly being different (upgrades just add the columns onto the end, whereas the default of a new install may be different).

If upgrading between any major versions of pg_partman (1.x -> 2.x, 2.x -> 3.x, etc), please carefully read all intervening version notes in the CHANGELOG, especially those notes for the major version. There are often additional instructions (Ex. updating trigger functions) and other important considerations for the updates.

EXAMPLE

First create a parent table with an appropriate column type for the partitioning type you will do. Apply all defaults, indexes, constraints, privileges & ownership to the parent table and they will be inherited to newly created child tables automatically (not already existing partitions, see docs for how to fix that). Here's one with columns that can be used for either

CREATE schema test;
CREATE TABLE test.part_test (col1 serial, col2 text, col3 timestamptz NOT NULL DEFAULT now());

Then just run the create_parent() function with the appropriate parameters

SELECT partman.create_parent('test.part_test', 'col3', 'partman', 'daily');
or
SELECT partman.create_parent('test.part_test', 'col1', 'partman', '100000');

This will turn your table into a parent table and premake 4 future partitions and also make 4 past partitions. To make new partitions, schedule the run_maintenance() function to run periodically or use the background worker settings in postgresql.conf (the latter is recommended).

This should be enough to get you started. Please see the pg_partman.md file in the doc folder for more information on the types of partitioning supported and what the parameters in the create_parent() function mean.

TESTING

This extension can use the pgTAP unit testing suite to evalutate if it is working properly (http://www.pgtap.org). WARNING: You MUST increase max_locks_per_transaction above the default value of 64. For me, 128 has worked well so far. This is due to the sub-partitioning tests that create/destroy several hundred tables in a single transaction. If you don't do this, you risk a cluster crash when running subpartitioning tests.