Base de données relationnelle
Find a file
Tom Lane 5586e42b34 Fix inadequate buffer locking in FSM and VM page re-initialization.
When reading an existing FSM or VM page that was found to be corrupt by the
buffer manager, the code applied PageInit() to reinitialize the page, but
did so without any locking.  There is thus a hazard that two backends might
concurrently do PageInit, which in itself would still be OK, but the slower
one might then zero over subsequent data changes applied by the faster one.
Even that is unlikely to be fatal; but it's not desirable, so add locking
to prevent it.

This does not add any locking overhead in the normal code path where the
page is OK.  It's not immediately obvious that that's safe, but I believe
it is, for reasons explained in the added comments.

Problem noted by R P Asim.  It's been like this for a long time, so
back-patch to all supported branches.

Discussion: https://postgr.es/m/CANXE4Te4G0TGq6cr0-TvwP0H4BNiK_-hB5gHe8mF+nz0mcYfMQ@mail.gmail.com
2018-07-13 11:53:11 -04:00
config Fix typos 2018-07-10 11:15:52 +02:00
contrib Block replication slot advance for these not yet reserving WAL 2018-07-11 08:57:18 +09:00
doc docs: Remove "New" description of the libpqxx interface 2018-07-13 11:16:56 -04:00
src Fix inadequate buffer locking in FSM and VM page re-initialization. 2018-07-13 11:53:11 -04:00
.dir-locals.el Make Emacs settings match perltidy configuration 2018-04-23 11:44:31 -04:00
.gitattributes Remove contrib/tsearch2. 2017-02-13 11:06:11 -05:00
.gitignore Support for optimizing and emitting code in LLVM JIT provider. 2018-03-22 11:05:22 -07:00
aclocal.m4 Add configure infrastructure (--with-llvm) to enable LLVM support. 2018-03-20 17:26:25 -07:00
configure Stamp 11beta2. 2018-06-25 11:09:49 -04:00
configure.in Stamp 11beta2. 2018-06-25 11:09:49 -04:00
COPYRIGHT Update copyright for 2018 2018-01-02 23:30:12 -05:00
GNUmakefile.in Have "make coverage" recurse into contrib as well 2016-09-05 18:44:36 -03:00
HISTORY Change documentation references to PG website to use https: not http: 2017-05-20 21:50:47 -04:00
Makefile Fix non-GNU makefiles for AIX make. 2017-11-30 00:57:22 -08:00
README Change documentation references to PG website to use https: not http: 2017-05-20 21:50:47 -04:00
README.git Change documentation references to PG website to use https: not http: 2017-05-20 21:50:47 -04:00

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/.