Release Notes

Restrict visibility of pg_stats_ext and pg_stats_ext_exprs entries to the table owner (Nathan Bossart)

These views failed to hide statistics for expressions that involve columns the accessing user does not have permission to read. View columns such as most_common_vals might expose security-relevant data. The potential interactions here are not fully clear, so in the interest of erring on the side of safety, make rows in these views visible only to the owner of the associated table.

The PostgreSQL Project thanks Lukas Fittl for reporting this problem. (CVE-2024-4317)

By itself, this fix will only fix the behavior in newly initdb'd database clusters. If you wish to apply this change in an existing cluster, you will need to do the following:

Fix INSERT from multiple VALUES rows into a target column that is a domain over an array or composite type (Tom Lane)

Such cases would either fail with surprising complaints about mismatched datatypes, or insert unexpected coercions that could lead to odd results.

Fix incorrect pruning of NULL partition when a table is partitioned on a boolean column and the query has a boolean IS NOT clause (David Rowley)

A NULL value satisfies a clause such as boolcol IS NOT FALSE, so pruning away a partition containing NULLs yielded incorrect answers.

Make ALTER FOREIGN TABLE SET SCHEMA move any owned sequences into the new schema (Tom Lane)

Moving a regular table to a new schema causes any sequences owned by the table to be moved to that schema too (along with indexes and constraints). This was overlooked for foreign tables, however.

Improve ALTER TABLE ... ALTER COLUMN TYPE's error message when there is a dependent function or publication (Tom Lane)

Fix EXPLAIN's counting of heap pages accessed by a bitmap heap scan (Melanie Plageman)

Previously, heap pages that contain no visible tuples were not counted; but it seems more consistent to count all pages returned by the bitmap index scan.

Avoid deadlock during removal of orphaned temporary tables (Mikhail Zhilin)

If the session that creates a temporary table crashes without removing the table, autovacuum will eventually try to remove the orphaned table. However, an incoming session that's been assigned the same temporary namespace will do that too. If a temporary table has a dependency (such as an owned sequence) then a deadlock could result between these two cleanup attempts.

Avoid race condition while examining per-relation frozen-XID values (Noah Misch)

VACUUM's computation of per-database frozen-XID values from per-relation values could get confused by a concurrent update of those values by another VACUUM.

Disallow converting a table to a view within an outer SQL command that is using that table (Tom Lane)

This avoids possible crashes.

Ensure that join conditions generated from equivalence classes are applied at the correct plan level (Tom Lane)

In versions before PostgreSQL 16, it was possible for generated conditions to be evaluated below outer joins when they should be evaluated above (after) the outer join, leading to incorrect query results. All versions have a similar hazard when considering joins to UNION ALL trees that have constant outputs for the join column in some SELECT arms.

Avoid unnecessary use of moving-aggregate mode with a non-moving window frame (Vallimaharajan G)

When a plain aggregate is used as a window function, and the window frame start is specified as UNBOUNDED PRECEDING, the frame's head cannot move so we do not need to use the special (and more expensive) moving-aggregate mode. This optimization was intended all along, but due to a coding error it never triggered.

Avoid use of already-freed data while planning partition-wise joins under GEQO (Tom Lane)

This would typically end in a crash or unexpected error message.

Avoid freeing still-in-use data in Memoize (Tender Wang, Andrei Lepikhov)

In production builds this error frequently didn't cause any problems, as the freed data would most likely not get overwritten before it was used.

Fix incorrectly-reported statistics kind codes in “requested statistics kind X is not yet built” error messages (David Rowley)

Be more careful with RECORD-returning functions in FROM (Tom Lane)

The output columns of such a function call must be defined by an AS clause that specifies the column names and data types. If the actual function output value doesn't match that, an error is supposed to be thrown at runtime. However, some code paths would examine the actual value prematurely, and potentially issue strange errors or suffer assertion failures if it doesn't match expectations.

Fix confusion about the return rowtype of SQL-language procedures (Tom Lane)

A procedure implemented in SQL language that returns a single composite-type column would cause an assertion failure or core dump.

Add protective stack depth checks to some recursive functions (Egor Chindyaskin)

Fix mis-rounding and overflow hazards in date_bin() (Moaaz Assali)

In the case where the source timestamp is before the origin timestamp and their difference is already an exact multiple of the stride, the code incorrectly subtracted the stride anyway. Also, detect some integer-overflow cases that would have produced incorrect results.

Detect integer overflow when adding or subtracting an interval to/from a timestamp (Joseph Koshakow)

Some cases that should cause an out-of-range error produced an incorrect result instead.

Avoid race condition in pg_get_expr() (Tom Lane)

If the relation referenced by the argument is dropped concurrently, the function's intention is to return NULL, but sometimes it failed instead.

Fix detection of old transaction IDs in XID status functions (Karina Litskevich)

Transaction IDs more than 2³¹ transactions in the past could be misidentified as recent, leading to misbehavior of pg_xact_status() or txid_status().

Ensure that a table's freespace map won't return a page that's past the end of the table (Ronan Dunklau)

Because the freespace map isn't WAL-logged, this was possible in edge cases involving an OS crash, a replica promote, or a PITR restore. The result would be a “could not read block” error.

Fix file descriptor leakage when an error is thrown while waiting in WaitEventSetWait (Etsuro Fujita)

Avoid corrupting exception stack if an FDW implements async append but doesn't configure any wait conditions for the Append plan node to wait for (Alexander Pyhalov)

Throw an error if an index is accessed while it is being reindexed (Tom Lane)

Previously this was just an assertion check, but promote it into a regular runtime error. This will provide a more on-point error message when reindexing a user-defined index expression that attempts to access its own table.

Ensure that index-only scans on name columns return a fully-padded value (David Rowley)

The value physically stored in the index is truncated, and previously a pointer to that value was returned to callers. This provoked complaints when testing under valgrind. In theory it could result in crashes, though none have been reported.

Fix crash with DSM allocations larger than 4GB (Heikki Linnakangas)

Disconnect if a new server session's client socket cannot be put into non-blocking mode (Heikki Linnakangas)

It was once theoretically possible for us to operate with a socket that's in blocking mode; but that hasn't worked fully in a long time, so fail at connection start rather than misbehave later.

Fix inadequate error reporting with OpenSSL 3.0.0 and later (Heikki Linnakangas, Tom Lane)

System-reported errors passed through by OpenSSL were reported with a numeric error code rather than anything readable.

Avoid concurrent calls to bindtextdomain() in libpq and ecpglib (Tom Lane)

Although GNU gettext's implementation seems to be fine with concurrent calls, the version available on Windows is not.

Fix crash in ecpg's preprocessor if the program tries to redefine a macro that was defined on the preprocessor command line (Tom Lane)

In ecpg, avoid issuing false “unsupported feature will be passed to server” warnings (Tom Lane)

Ensure that the string result of ecpg's intoasc() function is correctly zero-terminated (Oleg Tselebrovskiy)

Fix pg_dumpall so that role comments, if present, will be dumped regardless of the setting of --no-role-passwords (Daniel Gustafsson, Álvaro Herrera)

Fix PL/pgSQL's parsing of single-line comments (---style comments) following expressions (Erik Wienhold, Tom Lane)

This mistake caused parse errors if such a comment followed a WHEN expression in a PL/pgSQL CASE statement.

In contrib/amcheck, don't report false match failures due to short- versus long-header values (Andrey Borodin, Michael Zhilin)

A variable-length datum in a heap tuple or index tuple could have either a short or a long header, depending on compression parameters that applied when it was made. Treat these cases as equivalent rather than complaining if there's a difference.

Fix bugs in BRIN output functions (Tomas Vondra)

These output functions are only used for displaying index entries in contrib/pageinspect, so the errors are of limited practical concern.

In contrib/postgres_fdw, avoid emitting requests to sort by a constant (David Rowley)

This could occur in cases involving UNION ALL with constant-emitting subqueries. Sorting by a constant is useless of course, but it also risks being misinterpreted by the remote server, leading to “ORDER BY position N is not in select list” errors.

Make contrib/postgres_fdw set the remote session's time zone to GMT not UTC (Tom Lane)

This should have the same results for practical purposes. However, GMT is recognized by hard-wired code in the server, while UTC is looked up in the timezone database. So the old code could fail in the unlikely event that the remote server's timezone database is missing entries.

In contrib/xml2, avoid use of library functions that have been deprecated in recent versions of libxml2 (Dmitry Koval)

Fix incompatibility with LLVM 18 (Thomas Munro, Dmitry Dolgov)

Allow make check to work with the musl C library (Thomas Munro, Bruce Momjian, Tom Lane)