## E.2. Postgres Pro Standard 11.6.1

Release Date: 2019-12-12

### E.2.1. Overview

This release is based on PostgreSQL 11.6 and Postgres Pro Standard 11.5.4. All improvements inherited from PostgreSQL 11.6 are listed in PostgreSQL 11.6 Release Notes.

Major enhancements over Postgres Pro Standard 11.5.4 include:

- Added support for ALT Linux 9.

- Added support for Ubuntu 19.10.

- Ended support for Ubuntu 18.10.

- Modified the implementation of ICU default collations to ensure that the server can be started after the ICU library has been upgraded. For details, see the migration instructions below.

- Fixed an issue caused by removing self-joins from plans when using any condition other than `=` in the join operation.

- Forbade access to tables that belong to partition hierarchies in which both pg_pathman and standard PostgreSQL inheritance have been used for partitioning. Mixing different partitioning mechanisms in a single table hierarchy is unsupported and should have never been attempted. Previously, you could get duplicated query results from such table hierarchies.

- Reduced memory consumption when using ICU collations.

- Reduced planner's memory consumption and sped up `EXPLAIN ANALYZE` for queries with multiple `JOIN` clauses.

- Fixed incorrect memory allocation by optimizer in a background process.

- Improved stability of the pg_query_state module.

- Updated the mamonsu module to version 2.4.1. You can now convert all system and Postgres Pro metrics definitions provided by mamonsu to the format supported by the native Zabbix agent.

- Upgraded pgbouncer to version 1.11.0.

- Upgraded pg_probackup to version 2.2.5.

### E.2.2. Migration to Version 11.6.1

If you are upgrading from Postgres Pro Standard based on the same PostgreSQL major version, it is enough to install the new version into your current installation directory.

Starting from Postgres Pro Standard 11.6.1, the ICU library upgrade does not interfere with the server start. Before connecting to a database using ICU as the default collation, Postgres Pro compares this collation version to the one provided by the ICU library and displays a warning if the collation versions do not match; you may need to rebuild the objects that depend on the default collation if you think the collation change may affect the sort order of your data. To suppress these warnings, you can use the `ALTER COLLATION "default" REFRESH VERSION` command, as explained in ALTER COLLATION.

Since pg_probackup delivery model changed in Postgres Pro Standard 11.2.1, when upgrading from a lower version on ALT Linux and Debian-based systems, run `apt dist-upgrade` (or `apt-get dist-upgrade`) to ensure that all new dependencies are handled correctly. On Windows, you have to run a separate pg_probackup installer to complete the upgrade.

To migrate from PostgreSQL or a Postgres Pro Standard release based on a previous PostgreSQL major version, see the migration instructions for version 11. If you are opting for a dump/restore, make sure to use the `--add-collprovider` option to correctly choose the provider for the default collation of the migrated database.