Go to file
Peter Geoghegan cac37c1a1b Fix btmarkpos/btrestrpos array key wraparound bug.
nbtree's mark/restore processing failed to correctly handle an edge case
involving array key advancement and related search-type scan key state.
Scans with ScalarArrayScalarArrayOpExpr quals requiring mark/restore
processing (for a merge join) could incorrectly conclude that an
affected array/scan key must not have advanced during the time between
marking and restoring the scan's position.

As a result of all this, array key handling within btrestrpos could skip
a required call to _bt_preprocess_keys().  This confusion allowed later
primitive index scans to overlook tuples matching the true current array
keys.  The scan's search-type scan keys would still have spurious values
corresponding to the final array element(s) -- not values matching the
first/now-current array element(s).

To fix, remember that "array key wraparound" has taken place during the
ongoing btrescan in a flag variable stored in the scan's state, and use
that information at the point where btrestrpos decides if another call
to _bt_preprocess_keys is required.

Oversight in commit 70bc5833, which taught nbtree to handle array keys
during mark/restore processing, but missed this subtlety.  That commit
was itself a bug fix for an issue in commit 9e8da0f7, which taught
nbtree to handle ScalarArrayOpExpr quals natively.

Author: Peter Geoghegan <pg@bowt.ie>
Discussion: https://postgr.es/m/CAH2-WzkgP3DDRJxw6DgjCxo-cu-DKrvjEv_ArkP2ctBJatDCYg@mail.gmail.com
Backpatch: 11- (all supported branches).
2023-09-28 16:29:32 -07:00
config Use --strip-unneeded when stripping static libraries with GNU strip. 2023-04-20 18:12:48 -04:00
contrib unaccent: Tweak value of PYTHON when building without Python support 2023-09-27 14:41:21 +09:00
doc doc: clarify the effect of concurrent work_mem allocations 2023-09-26 19:44:22 -04:00
src Fix btmarkpos/btrestrpos array key wraparound bug. 2023-09-28 16:29:32 -07:00
.cirrus.star ci: Prepare to make compute resources for CI configurable 2023-08-23 15:15:29 -07:00
.cirrus.tasks.yml ci: Make compute resources for CI configurable 2023-08-23 15:15:29 -07:00
.cirrus.yml ci: Make compute resources for CI configurable 2023-08-23 15:15:29 -07:00
.dir-locals.el Make Emacs perl-mode indent more like perltidy. 2019-01-13 11:32:31 -08:00
.editorconfig Add .editorconfig 2019-12-18 09:13:13 +01:00
.git-blame-ignore-revs Backpatch addition of .git-blame-ignore-revs 2022-08-05 19:36:24 +02:00
.gitattributes Remove trailing whitespace from *.sgml files. 2022-04-20 11:04:49 -04:00
.gitignore Add portlock directory to .gitignore 2022-11-26 07:47:01 -05:00
COPYRIGHT Update copyright for 2023 2023-01-02 15:00:37 -05:00
GNUmakefile.in Remove temporary portlock directory during make [dist]clean. 2022-11-26 10:30:46 -05:00
HISTORY Canonicalize some URLs 2020-02-10 20:47:50 +01:00
Makefile Dynamically find correct installation docs in Makefile. 2022-01-19 14:48:25 +01:00
README Canonicalize some URLs 2020-02-10 20:47:50 +01:00
README.git Canonicalize some URLs 2020-02-10 20:47:50 +01:00
aclocal.m4 Probe $PROVE not $PERL while checking for modules needed by TAP tests. 2021-11-22 12:54:52 -05:00
configure Stamp 15.4. 2023-08-07 16:08:18 -04:00
configure.ac Stamp 15.4. 2023-08-07 16:08:18 -04:00

README

PostgreSQL Database Management System
=====================================

This directory contains the source code distribution of the PostgreSQL
database management system.

PostgreSQL is an advanced object-relational database management system
that supports an extended subset of the SQL standard, including
transactions, foreign keys, subqueries, triggers, user-defined types
and functions.  This distribution also contains C language bindings.

PostgreSQL has many language interfaces, many of which are listed here:

	https://www.postgresql.org/download/

See the file INSTALL for instructions on how to build and install
PostgreSQL.  That file also lists supported operating systems and
hardware platforms and contains information regarding any other
software packages that are required to build or run the PostgreSQL
system.  Copyright and license information can be found in the
file COPYRIGHT.  A comprehensive documentation set is included in this
distribution; it can be read as described in the installation
instructions.

The latest version of this software may be obtained at
https://www.postgresql.org/download/.  For more information look at our
web site located at https://www.postgresql.org/.