Go to file
Tom Lane bc7885b7f5 Work around portability issue with newer versions of mktime().
Recent glibc versions have made mktime() fail if tm_isdst is
inconsistent with the prevailing timezone; in particular it fails for
tm_isdst = 1 when the zone is UTC.  (This seems wildly inconsistent
with the POSIX-mandated treatment of "incorrect" values for the other
fields of struct tm, so if you ask me it's a bug, but I bet they'll
say it's intentional.)  This has been observed to cause cosmetic
problems when pg_restore'ing an archive created in a different
timezone.

To fix, do mktime() using the field values from the archive, and if
that fails try again with tm_isdst = -1.  This will give a result
that's off by the UTC-offset difference from the original zone, but
that was true before, too.  It's not terribly critical since we don't
do anything with the result except possibly print it.  (Someday we
should flush this entire bit of logic and record a standard-format
timestamp in the archive instead.  That's not okay for a back-patched
bug fix, though.)

Also, guard our only other use of mktime() by having initdb's
build_time_t() set tm_isdst = -1 not 0.  This case could only have
an issue in zones that are DST year-round; but I think some do exist,
or could in future.

Per report from Wells Oliver.  Back-patch to all supported
versions, since any of them might need to run with a newer glibc.

Discussion: https://postgr.es/m/CAOC+FBWDhDHO7G-i1_n_hjRzCnUeFO+H-Czi1y10mFhRWpBrew@mail.gmail.com
2021-06-13 14:32:42 -04:00
config jit: configure: Explicitly reference 'native' component. 2020-12-07 18:32:56 -08:00
contrib Stabilize contrib/seg regression test. 2021-06-07 14:52:56 -04:00
doc Avoid misbehavior when persisting a non-stable cursor. 2021-06-08 17:50:15 -04:00
src Work around portability issue with newer versions of mktime(). 2021-06-13 14:32:42 -04:00
.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
.gitattributes gitattributes: Add new file 2019-11-12 08:13:55 +01:00
.gitignore Support for optimizing and emitting code in LLVM JIT provider. 2018-03-22 11:05:22 -07:00
COPYRIGHT Update copyright for 2021 2021-01-02 13:06:24 -05:00
GNUmakefile.in Make install-tests target work with vpath builds 2020-05-31 18:33:00 -04:00
HISTORY Canonicalize some URLs 2020-02-10 20:47:50 +01:00
Makefile Don't unset MAKEFLAGS in non-GNU Makefile. 2019-06-25 09:36:21 +12:00
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 Remove configure-time probe for DocBook DTD. 2020-11-30 15:24:13 -05:00
configure Add fallback implementation for setenv() 2021-06-01 09:27:25 +09:00
configure.in Add fallback implementation for setenv() 2021-06-01 09:27:25 +09:00

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/.