## E.16. Release 10.12

Release date: 2020-02-13

This release contains a variety of fixes from 10.11. For information about new features in major release 10, see Section E.28.

### E.16.1. Migration to Version 10.12

A dump/restore is not required for those running 10.X.

However, if you are upgrading from a version earlier than 10.11, see Section E.17.

### E.16.2. Changes

- Add missing permissions checks for `ALTER ... DEPENDS ON EXTENSION` (Álvaro Herrera)

  Marking an object as dependent on an extension did not have any privilege check whatsoever. This oversight allowed any user to mark routines, triggers, materialized views, or indexes as droppable by anyone able to drop an extension. Require that the calling user own the specified object (and hence have privilege to drop it). (CVE-2020-1720)

- Fix logical replication subscriber code to execute per-column `UPDATE` triggers when appropriate (Peter Eisentraut)

- Avoid failure in logical decoding when a large transaction must be spilled into many separate temporary files (Amit Khandekar)

- Fix possible crash or data corruption when a logical replication subscriber processes a row update (Tom Lane, Tomas Vondra)

  This bug caused visible problems only if the subscriber's table contained columns that were not being copied from the publisher and had pass-by-reference data types.

- Fix crash in logical replication subscriber after DDL changes on a subscribed relation (Jehan-Guillaume de Rorthais, Vignesh C)

- Fix failure in logical replication publisher after a database crash and restart (Vignesh C)

- Improve efficiency of logical replication with `REPLICA IDENTITY FULL` (Konstantin Knizhnik)

  When searching for an existing tuple during an update or delete operation, return the first matching tuple not the last one.

- Prevent premature shutdown of a Gather or GatherMerge plan node that is underneath a Limit node (Amit Kapila)

  This avoids failure if such a plan node needs to be scanned more than once, as for instance if it is on the inside of a nestloop.

- Avoid memory leak when there are no free dynamic shared memory slots (Thomas Munro)

- Ignore the `CONCURRENTLY` option when performing an index creation, drop, or rebuild on a temporary table (Michael Paquier, Heikki Linnakangas, Andres Freund)

  This avoids strange failures if the temporary table has an `ON COMMIT` action. There is no benefit in using `CONCURRENTLY` for a temporary table anyway, since other sessions cannot access the table, making the extra processing pointless.

- Fix possible failure when resetting expression indexes on temporary tables that are marked `ON COMMIT DELETE ROWS` (Tom Lane)

- Fix possible crash in BRIN index operations with `box`, `range` and `inet` data types (Heikki Linnakangas)

- Fix handling of deleted pages in GIN indexes (Alexander Korotkov)

  Avoid possible deadlocks, incorrect updates of a deleted page's state, and failure to traverse through a recently-deleted page.

- Fix possible crash with a SubPlan (sub-`SELECT`) within a multi-row `VALUES` list (Tom Lane)

- Fix crash after FileClose() failure (Noah Misch)

  This issue could only be observed with `data_sync_retry` enabled, since otherwise FileClose() failure would be reported as a PANIC.

- Fix unlikely crash with pass-by-reference aggregate transition states (Andres Freund, Teodor Sigaev)

- Improve error reporting in `to_date()` and `to_timestamp()` (Tom Lane, Álvaro Herrera)

  Reports about incorrect month or day names in input strings could truncate the input in the middle of a multi-byte character, leading to an improperly encoded error message that could cause follow-on failures. Truncate at the next whitespace instead.

- Fix off-by-one result for `EXTRACT(ISOYEAR FROM `timestamp`)` for BC dates (Tom Lane)

- Avoid stack overflow in `information_schema` views when a self-referential view exists in the system catalogs (Tom Lane)

  A self-referential view can't work; it will always result in infinite recursion. We handled that situation correctly when trying to execute the view, but not when inquiring whether it is automatically updatable.

- Ensure that walsender processes always show NULL for transaction start time in `pg_stat_activity` (Álvaro Herrera)

  Previously, the `xact_start` column would sometimes show the process start time.

- Improve performance of hash joins with very large inner relations (Thomas Munro)

- Fix edge-case crashes and misestimations in selectivity calculations for the `<@` and `@>` range operators (Michael Paquier, Andrey Borodin, Tom Lane)

- Ignore system columns when applying most-common-value extended statistics (Tomas Vondra)

  This prevents “negative bitmapset member not allowed” planner errors for affected queries.

- Fix BRIN index logic to support hypothetical BRIN indexes (Julien Rouhaud, Heikki Linnakangas)

  Previously, if an “index adviser” extension tried to get the planner to produce a plan involving a hypothetical BRIN index, that would fail, because the BRIN cost estimation code would always try to physically access the index's metapage. Now it checks to see if the index is only hypothetical, and uses default assumptions about the index parameters if so.

- Improve error reporting for attempts to use automatic updating of views with conditional `INSTEAD` rules (Dean Rasheed)

  This has never been supported, but previously the error was thrown only at execution time, so that it could be masked by planner errors.

- Prevent a composite type from being included in itself indirectly via a range type (Tom Lane, Julien Rouhaud)

- Disallow partition key expressions that return pseudo-types, such as `record` (Tom Lane)

- Fix error reporting for index expressions of prohibited types (Amit Langote)

- Fix dumping of views that contain only a `VALUES` list to handle cases where a view output column has been renamed (Tom Lane)

- Ensure that data types and collations used in `XMLTABLE` constructs are accounted for when computing dependencies of a view or rule (Tom Lane)

  Previously it was possible to break a view using `XMLTABLE` by dropping a type, if the type was not otherwise referenced in the view. This fix does not correct the dependencies already recorded for existing views, only for newly-created ones.

- Prevent unwanted downcasing and truncation of RADIUS authentication parameters (Marcos David)

  The `pg_hba.conf` parser mistakenly treated these fields as SQL identifiers, which in general they aren't.

- Transmit incoming `NOTIFY` messages to the client before sending `ReadyForQuery`, rather than after (Tom Lane)

  This change ensures that, with libpq and other client libraries that act similarly to it, any notifications received during a transaction will be available by the time the client thinks the transaction is complete. This probably makes no difference in practical applications (which would need to cope with asynchronous notifications in any case); but it makes it easier to build test cases with reproducible behavior.

- Allow libpq to parse all GSS-related connection parameters even when the GSSAPI code hasn't been compiled in (Tom Lane)

  This makes the behavior similar to our SSL support, where it was long ago deemed to be a good idea to always accept all the related parameters, even if some are ignored or restricted due to lack of the feature in a particular build.

- Fix incorrect handling of `%b` and `%B` format codes in ecpg's `PGTYPEStimestamp_fmt_asc()` function (Tomas Vondra)

  Due to an off-by-one error, these codes would print the wrong month name, or possibly crash.

- Fix parallel pg_dump/pg_restore to more gracefully handle failure to create worker processes (Tom Lane)

- Prevent possible crash or lockup when attempting to terminate a parallel pg_dump/pg_restore run via a signal (Tom Lane)

- In pg_upgrade, look inside arrays and ranges while searching for non-upgradable data types in tables (Tom Lane)

- Apply more thorough syntax checking to createuser's `--connection-limit` option (Álvaro Herrera)

- Avoid crash in `postgres_fdw` when trying to send a command like `UPDATE remote_tab SET (x,y) = (SELECT ...)` to the remote server (Tom Lane)

- In `contrib/dict_int`, reject `maxlen` settings less than one (Tomas Vondra)

  This prevents a possible crash with silly settings for that parameter.

- Disallow NULL category values in `contrib/tablefunc`'s `crosstab()` function (Joe Conway)

  This case never worked usefully, and it would crash on some platforms.

- Mark some timeout and statistics-tracking GUC variables as `PGDLLIMPORT`, to allow extensions to access them on Windows (Pascal Legrand)

  This applies to `idle_in_transaction_session_timeout`, `lock_timeout`, `statement_timeout`, `track_activities`, `track_counts`, and `track_functions`.

- Avoid memory leak in sanity checks for “slab” memory contexts (Tomas Vondra)

  This isn't an issue for production builds, since they wouldn't ordinarily have memory context checking enabled; but the leak could be quite severe in a debug build.

- Fix multiple statistics entries reported by the LWLock statistics mechanism (Fujii Masao)

  The LWLock statistics code (which is not built by default; it requires compiling with `-DLWLOCK_STATS`) could report multiple entries for the same LWLock and backend process, as a result of faulty hashtable key creation.

- Fix race condition that led to delayed delivery of interprocess signals on Windows (Amit Kapila)

  This caused visible timing oddities in `NOTIFY`, and perhaps other misbehavior.

- On Windows, retry a few times after an `ERROR_ACCESS_DENIED` file access failure (Alexander Lakhin, Tom Lane)

  This helps cope with cases where a file open attempt fails because the targeted file is flagged for deletion but not yet actually gone. pg_ctl, for example, frequently failed with such an error when probing to see if the postmaster had shut down yet.