## Appendix E. Release Notes

The release notes contain the significant changes in each Postgres Pro Standard release, with major features and migration issues listed at the top. The release notes do not contain changes that affect only a few users or changes that are internal and therefore not user-visible. For example, the optimizer is improved in almost every release, but the improvements are usually observed by users as simply faster queries.

## E.1. Postgres Pro Standard 10.12.1

Release Date: 2020-02-26

### E.1.1. Overview

This release is based on PostgreSQL 10.12 and Postgres Pro Standard 10.11.1. All changes inherited from PostgreSQL 10.12 are listed in PostgreSQL 10.12 Release Notes. Other major changes and enhancements are as follows:

- Increased the maximum value of the track_activity_query_size parameter to 1MB. In vanilla PostgreSQL, this change is targeted for version 13.

- Fixed planner's optimization to correctly take into account similar `OR` clauses if they reference columns that are different, but have the same position in different indexes.

- Fixed the `mchar` extension to correctly handle the `ESCAPE` clause in `SIMILAR TO` regular expressions.

- Improved query performance with row-level security policy enabled by correctly marking numeric comparison functions as leakproof.

- Upgraded pg_probackup to version 2.2.7.

- Upgraded mamonsu to version 2.4.4.

### E.1.2. Migration to Version 10.12.1

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

While functions `numeric_eq`, `numeric_ne`, `numeric_gt`, `numeric_ge`, `numeric_lt`, and `numeric_le` are actually leakproof, they were not marked as such in Postgres Pro Standard 10.11.1 or lower, which could lead to incorrect query optimization. In particular, it negatively affected query execution if row-level security policy was in use. Version 10.12.1 repairs this issue for new installations by correcting the initial catalog data, but existing installations will still have incorrect markings unless you update `pg_proc` entries for these functions. You can run pg_upgrade to upgrade your server instance to a version containing the corrected initial data, or manually correct these entries in each database of the installation using the `ALTER FUNCTION` command. For example:

    ALTER FUNCTION pg_catalog.numeric_eq VOLATILE

Starting from Postgres Pro Standard 10.11.1, 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 10.7.1, 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.

When upgrading from version 10.3.2 or lower, you must call the `REINDEX` command for indexes that used `mchar` or `mvarchar` types. Besides, if you have been using `pg_repack` on Debian-based systems, you have to reinstall its package manually when upgrading to this version since its package got renamed to `pg-repack-std-10`.

To migrate from PostgreSQL or a Postgres Pro Standard release based on a previous PostgreSQL major version, see the migration instructions for version 10. 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.