postgres

Masahiko Sawada f7d3caf9dd Fix possibility of logical decoding partial transaction changes. When creating and initializing a logical slot, the restart_lsn is set to the latest WAL insertion point (or the latest replay point on standbys). Subsequently, WAL records are decoded from that point to find the start point for extracting changes in the DecodingContextFindStartpoint() function. Since the initial restart_lsn could be in the middle of a transaction, the start point must be a consistent point where we won't see the data for partial transactions. Previously, when not building a full snapshot, serialized snapshots were restored, and the SnapBuild jumps to the consistent state even while finding the start point. Consequently, the slot's restart_lsn and confirmed_flush could be set to the middle of a transaction. This could lead to various unexpected consequences. Specifically, there were reports of logical decoding decoding partial transactions, and assertion failures occurred because only subtransactions were decoded without decoding their top-level transaction until decoding the commit record. To resolve this issue, the changes prevent restoring the serialized snapshot and jumping to the consistent state while finding the start point. On v17 and HEAD, a flag indicating whether snapshot restores should be skipped has been added to the SnapBuild struct, and SNAPBUILD_VERSION has been bumpded. On backbranches, the flag is stored in the LogicalDecodingContext instead, preserving on-disk compatibility. Backpatch to all supported versions. Reported-by: Drew Callahan Reviewed-by: Amit Kapila, Hayato Kuroda Discussion: https://postgr.es/m/2444AA15-D21B-4CCE-8052-52C7C2DAFE5C%40amazon.com Backpatch-through: 12		12 months ago
config	Log LLVM library version in configure output.	2 years ago
contrib	Fix possibility of logical decoding partial transaction changes.	12 months ago
doc	Doc: small improvements in discussion of geometric data types.	1 year ago
src	Fix possibility of logical decoding partial transaction changes.	12 months ago
.dir-locals.el	Make Emacs perl-mode indent more like perltidy.	7 years ago
.editorconfig	Add .editorconfig	6 years ago
.git-blame-ignore-revs	Backpatch addition of .git-blame-ignore-revs	3 years ago
.gitattributes	gitattributes: Add new entry to silence whitespace error	4 years ago
.gitignore	Add portlock directory to .gitignore	3 years ago
COPYRIGHT	Update copyright for 2024	2 years ago
GNUmakefile.in	Remove temporary portlock directory during make [dist]clean.	3 years ago
HISTORY	Canonicalize some URLs	5 years ago
Makefile	Don't unset MAKEFLAGS in non-GNU Makefile.	6 years ago
README	Canonicalize some URLs	5 years ago
README.git	Canonicalize some URLs	5 years ago
aclocal.m4	Probe $PROVE not $PERL while checking for modules needed by TAP tests.	4 years ago
configure	Stamp 14.12.	1 year ago
configure.ac	Stamp 14.12.	1 year ago

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/.