PostgreSQL 12.2, 11.7, 10.12, 9.6.17, 9.5.21, and 9.4.26 Released!

The PostgreSQL Global Development Group has released an update to all
supported versions of our database system, including 12.2, 11.7, 10.12,
9.6.17, 9.5.21, and 9.4.26. This release fixes one security issue found
in the PostgreSQL server and over 75 bugs reported over the last three
months.

Users should plan to update as soon as possible.

PostgreSQL 9.4 Now EOL
----------------------

This is the last release for PostgreSQL 9.4, which will no longer
receive security updates and bug fixes. PostgreSQL 9.4 introduced new
features such as JSONB support, the `ALTER SYSTEM` command, the ability
to stream logical changes to an output plugin, and more:

https://www.postgresql.org/about/news/1557/
https://www.postgresql.org/docs/9.4/release-9-4.html

While we are very proud of this release, these features are also found
in newer versions of PostgreSQL. Many of these features have also
received improvements, and, per our versioning policy, it is time to
retire PostgreSQL 9.4.

To receive continued support, we suggest that you make plans to upgrade
to a newer, supported version of PostgreSQL. Please see the PostgreSQL
versioning policy for more information.

Security Issues
---------------

* CVE-2020-1720: `ALTER ... DEPENDS ON EXTENSION` is missing
authorization checks.

Versions Affected: 9.6 - 12

The `ALTER ... DEPENDS ON EXTENSION` sub-commands do not perform
authorization checks, which can allow an unprivileged user to drop any
function, procedure, materialized view, index, or trigger under certain
conditions. This attack is possible if an administrator has installed an
extension and an unprivileged user can `CREATE`, or an extension owner
either executes `DROP EXTENSION` predictably or can be convinced to
execute `DROP EXTENSION`.

The PostgreSQL project thanks Tom Lane for reporting this problem.

Bug Fixes and Improvements
--------------------------

This update also fixes over 75 bugs that were reported in the last
several months. Some of these issues affect only version 12, but may
also affect all supported versions.

Some of these fixes include:

* Fix for partitioned tables with foreign-key references where `TRUNCATE
... CASCADE` would not remove all data. If you have previously used
`TRUNCATE ... CASCADE` on a partitioned table with foreign-key
references please see the "Updating" section for verification and
cleanup steps.
* Fix failure to add foreign key constraints to table with
sub-partitions (aka a multi-level partitioned table). If you have
previously used this functionality, you can fix it by either detaching
and re-attaching the affected partition, or by dropping and re-adding
the foreign key constraint to the parent table. You can find more
information on how to perform these steps in the ALTER TABLE
documentation: https://www.postgresql.org/docs/current/sql-altertable.html
* Fix performance issue for partitioned tables introduced by the fix for
CVE-2017-7484 that now allows the planner to use statistics on a child
table for a column that the user is granted access to on the parent
table when the query contains a leaky operator.
* Several other fixes and changes for partitioned tables, including
disallowing partition key expressions that return pseudo-types, such as
`RECORD`.
* Fix for logical replication subscribers for executing per-column
`UPDATE` triggers.
* Fix for several crashes and failures for logical replication
subscribers and publishers.
* Improve efficiency of logical replication with `REPLICA IDENTITY FULL`.
* Ensure that calling `pg_replication_slot_advance()` on a physical
replication slot will persist changes across restarts.
* Several fixes for the walsender processes.
* Improve performance of hash joins with very large inner relations.
* Fix placement of "Subplans Removed" field in EXPLAIN output by placing
it with its parent Append or MergeAppend plan.
* Several fixes for parallel query plans.
* Several fixes for query planner errors, including one that affected
joins to single-row subqueries.
* Several fixes for MCV extend statistics, including one for incorrect
estimation for OR clauses.
* Improve efficiency of parallel hash join on CPUs with many cores.
* Ignore the `CONCURRENTLY` option when performing an index creation,
drop, or reindex on a temporary table.
* Fall back to non-parallel index builds when a parallelized CREATE
INDEX has no free dynamic shared memory slots.
* Several fixes for GiST & GIN indexes.
* Fix possible crash in BRIN index operations with `box`, `range` and
`inet` data types.
* Fix support for BRIN hypothetical indexes.
* Fix failure in `ALTER TABLE` when a column referenced in a `GENERATED`
expression is added or changed in type earlier in the same `ALTER TABLE`
statement.
* Fix handling of multiple `AFTER ROW` triggers on a foreign table.
* Fix off-by-one result for `EXTRACT(ISOYEAR FROM timestamp)` for BC dates.
* Prevent unwanted lowercasing and truncation of RADIUS authentication
parameters in the `pg_hba.conf` file.
* Several fixes for GSSAPI support, including having libpq accept all
GSS-related connection parameters even if the GSSAPI code is not
compiled in.
* Several fixes for `pg_dump` and `pg_restore` when run in parallel mode.
* Fix crash with `postgres_fdw` when trying to execute a remote query on
the remote server such as `UPDATE remote_tab SET (x,y) = (SELECT ...)`.
* Disallow NULL category values in the `crosstab()` function of
`contrib/tablefunc` to prevent crashes.
* Several fixes for Windows, including a race condition that could cause
timing oddities with `NOTIFY`.
* Several ecpg fixes.

For the full list of changes available, please review the release notes:

https://www.postgresql.org/docs/current/release.html

Updating
--------

All PostgreSQL update releases are cumulative. As with other minor
releases, users are not required to dump and reload their database or
use `pg_upgrade` in order to apply this update release; you may simply
shutdown PostgreSQL and update its binaries.

Users who have skipped one or more update releases may need to run
additional, post-update steps; please see the release notes for earlier
versions for details.

If you had previously executed `TRUNCATE ... CASCADE` on a sub-partition
of a partitioned table, and the partitioned table has a foreign-key
reference from another table, you may have to execute the `TRUNCATE` on
the other table, or execute a `DELETE` if you have added rows since
running `TRUNCATE ... CASCADE`. The issue that caused this is fixed in
this release, but you will have to perform this step to ensure all of
your data is cleaned up.

For more details, please see the release notes.

Links
-----
* Download: https://www.postgresql.org/download/
* Release Notes: https://www.postgresql.org/docs/current/release.html
* Security Page: https://www.postgresql.org/support/security/
* Versioning Policy: https://www.postgresql.org/support/versioning/
* Follow @postgresql on Twitter: https://twitter.com/postgresql