postgresql/contrib
Tom Lane 4b3b44b141 Support timezone abbreviations that sometimes change.
Up to now, PG has assumed that any given timezone abbreviation (such as
"EDT") represents a constant GMT offset in the usage of any particular
region; we had a way to configure what that offset was, but not for it
to be changeable over time.  But, as with most things horological, this
view of the world is too simplistic: there are numerous regions that have
at one time or another switched to a different GMT offset but kept using
the same timezone abbreviation.  Almost the entire Russian Federation did
that a few years ago, and later this month they're going to do it again.
And there are similar examples all over the world.

To cope with this, invent the notion of a "dynamic timezone abbreviation",
which is one that is referenced to a particular underlying timezone
(as defined in the IANA timezone database) and means whatever it currently
means in that zone.  For zones that use or have used daylight-savings time,
the standard and DST abbreviations continue to have the property that you
can specify standard or DST time and get that time offset whether or not
DST was theoretically in effect at the time.  However, the abbreviations
mean what they meant at the time in question (or most recently before that
time) rather than being absolutely fixed.

The standard abbreviation-list files have been changed to use this behavior
for abbreviations that have actually varied in meaning since 1970.  The
old simple-numeric definitions are kept for abbreviations that have not
changed, since they are a bit faster to resolve.

While this is clearly a new feature, it seems necessary to back-patch it
into all active branches, because otherwise use of Russian zone
abbreviations is going to become even more problematic than it already was.
This change supersedes the changes in commit 513d06ded et al to modify the
fixed meanings of the Russian abbreviations; since we've not shipped that
yet, this will avoid an undesirably incompatible (not to mention incorrect)
change in behavior for timestamps between 2011 and 2014.

This patch makes some cosmetic changes in ecpglib to keep its usage of
datetime lookup tables as similar as possible to the backend code, but
doesn't do anything about the increasingly obsolete set of timezone
abbreviation definitions that are hard-wired into ecpglib.  Whatever we
do about that will likely not be appropriate material for back-patching.
Also, a potential free() of a garbage pointer after an out-of-memory
failure in ecpglib has been fixed.

This patch also fixes pre-existing bugs in DetermineTimeZoneOffset() that
caused it to produce unexpected results near a timezone transition, if
both the "before" and "after" states are marked as standard time.  We'd
only ever thought about or tested transitions between standard and DST
time, but that's not what's happening when a zone simply redefines their
base GMT offset.

In passing, update the SGML documentation to refer to the Olson/zoneinfo/
zic timezone database as the "IANA" database, since it's now being
maintained under the auspices of IANA.
2014-10-16 15:22:13 -04:00
..
adminpack Create function prototype as part of PG_FUNCTION_INFO_V1 macro 2014-04-18 00:03:19 -04:00
auth_delay Limit values of archive_timeout, post_auth_delay, auth_delay.milliseconds. 2012-11-18 17:15:06 -05:00
auto_explain Print planning time only in EXPLAIN ANALYZE, not plain EXPLAIN. 2014-10-15 18:50:16 -04:00
btree_gin Fix typos in some error messages thrown by extension scripts when fed to psql. 2014-08-25 18:30:28 +02:00
btree_gist Support timezone abbreviations that sometimes change. 2014-10-16 15:22:13 -04:00
chkpass Fix typos in some error messages thrown by extension scripts when fed to psql. 2014-08-25 18:30:28 +02:00
citext Fix citext upgrade script for disallowance of oidvector element assignment. 2014-08-28 18:21:11 -04:00
cube Fix typos in some error messages thrown by extension scripts when fed to psql. 2014-08-25 18:30:28 +02:00
dblink Fix typos in some error messages thrown by extension scripts when fed to psql. 2014-08-25 18:30:28 +02:00
dict_int Fix typos in some error messages thrown by extension scripts when fed to psql. 2014-08-25 18:30:28 +02:00
dict_xsyn Fix typos in some error messages thrown by extension scripts when fed to psql. 2014-08-25 18:30:28 +02:00
dummy_seclabel Update copyright for 2014 2014-01-07 16:05:30 -05:00
earthdistance Fix typos in some error messages thrown by extension scripts when fed to psql. 2014-08-25 18:30:28 +02:00
file_fdw pgindent run for 9.4 2014-05-06 12:12:18 -04:00
fuzzystrmatch Fix typos in some error messages thrown by extension scripts when fed to psql. 2014-08-25 18:30:28 +02:00
hstore Fix typos in some error messages thrown by extension scripts when fed to psql. 2014-08-25 18:30:28 +02:00
intagg Fix typos in some error messages thrown by extension scripts when fed to psql. 2014-08-25 18:30:28 +02:00
intarray Fix typos in some error messages thrown by extension scripts when fed to psql. 2014-08-25 18:30:28 +02:00
isn Fix typos in some error messages thrown by extension scripts when fed to psql. 2014-08-25 18:30:28 +02:00
lo Fix typos in some error messages thrown by extension scripts when fed to psql. 2014-08-25 18:30:28 +02:00
ltree Fix typos in some error messages thrown by extension scripts when fed to psql. 2014-08-25 18:30:28 +02:00
oid2name pgindent run for 9.4 2014-05-06 12:12:18 -04:00
pageinspect Fix typos in some error messages thrown by extension scripts when fed to psql. 2014-08-25 18:30:28 +02:00
passwordcheck Update copyright for 2014 2014-01-07 16:05:30 -05:00
pg_archivecleanup pgindent run for 9.4 2014-05-06 12:12:18 -04:00
pg_buffercache Fix typos in some error messages thrown by extension scripts when fed to psql. 2014-08-25 18:30:28 +02:00
pg_freespacemap Fix typos in some error messages thrown by extension scripts when fed to psql. 2014-08-25 18:30:28 +02:00
pg_prewarm pgindent run for 9.4 2014-05-06 12:12:18 -04:00
pg_standby Remove MinGW readdir/errno bug workaround fixed on 2003-10-10 2014-03-21 13:47:37 -04:00
pg_stat_statements Fix typos in some error messages thrown by extension scripts when fed to psql. 2014-08-25 18:30:28 +02:00
pg_test_fsync pgindent run for 9.4 2014-05-06 12:12:18 -04:00
pg_test_timing Remove undocumented -h (help) option 2013-07-01 12:40:33 -04:00
pg_trgm Fix typos in some error messages thrown by extension scripts when fed to psql. 2014-08-25 18:30:28 +02:00
pg_upgrade pg_upgrade: have pg_upgrade fail for old 9.4 JSONB format 2014-09-29 20:19:59 -04:00
pg_upgrade_support Create function prototype as part of PG_FUNCTION_INFO_V1 macro 2014-04-18 00:03:19 -04:00
pg_xlogdump pgindent run for 9.4 2014-05-06 12:12:18 -04:00
pgbench Fix typo in error message. 2014-10-02 15:52:11 +03:00
pgcrypto Fix typos in some error messages thrown by extension scripts when fed to psql. 2014-08-25 18:30:28 +02:00
pgrowlocks Fix typos in some error messages thrown by extension scripts when fed to psql. 2014-08-25 18:30:28 +02:00
pgstattuple Fix typos in some error messages thrown by extension scripts when fed to psql. 2014-08-25 18:30:28 +02:00
postgres_fdw pgindent run for 9.4 2014-05-06 12:12:18 -04:00
seg Fix typos in some error messages thrown by extension scripts when fed to psql. 2014-08-25 18:30:28 +02:00
sepgsql pgindent run for 9.4 2014-05-06 12:12:18 -04:00
spi Fix typos in some error messages thrown by extension scripts when fed to psql. 2014-08-25 18:30:28 +02:00
sslinfo Fix typos in some error messages thrown by extension scripts when fed to psql. 2014-08-25 18:30:28 +02:00
start-scripts doc: Reflect renaming of Mac OS X to OS X 2014-09-09 13:58:50 -04:00
tablefunc Fix typos in some error messages thrown by extension scripts when fed to psql. 2014-08-25 18:30:28 +02:00
tcn pgindent run for 9.4 2014-05-06 12:12:18 -04:00
test_decoding Improve documentation about binary/textual output mode for output plugins. 2014-10-01 13:21:59 +02:00
test_parser Fix typos in some error messages thrown by extension scripts when fed to psql. 2014-08-25 18:30:28 +02:00
test_shm_mq pgindent run for 9.4 2014-05-06 12:12:18 -04:00
tsearch2 Fix typos in some error messages thrown by extension scripts when fed to psql. 2014-08-25 18:30:28 +02:00
unaccent Fix typos in some error messages thrown by extension scripts when fed to psql. 2014-08-25 18:30:28 +02:00
uuid-ossp Fix typos in some error messages thrown by extension scripts when fed to psql. 2014-08-25 18:30:28 +02:00
vacuumlo Centralize getopt-related declarations in a new header file pg_getopt.h. 2014-02-15 14:31:30 -05:00
worker_spi worker_spi: Initialize bgw_notify_pid in all cases. 2014-05-26 22:56:28 -04:00
xml2 Fix typos in some error messages thrown by extension scripts when fed to psql. 2014-08-25 18:30:28 +02:00
contrib-global.mk
Makefile Support BSD and e2fsprogs UUID libraries alongside OSSP UUID library. 2014-05-27 19:42:08 -04:00
README Rename 'gmake' to 'make' in docs and recommended commands 2014-02-12 17:29:19 -05:00

The PostgreSQL contrib tree
---------------------------

This subtree contains porting tools, analysis utilities, and plug-in
features that are not part of the core PostgreSQL system, mainly
because they address a limited audience or are too experimental to be
part of the main source tree.  This does not preclude their
usefulness.

User documentation for each module appears in the main SGML
documentation.

When building from the source distribution, these modules are not
built automatically, unless you build the "world" target.  You can
also build and install them all by running "make all" and "make
install" in this directory; or to build and install just one selected
module, do the same in that module's subdirectory.

Some directories supply new user-defined functions, operators, or
types.  To make use of one of these modules, after you have installed
the code you need to register the new SQL objects in the database
system by executing a CREATE EXTENSION command.  In a fresh database,
you can simply do

    CREATE EXTENSION module_name;

See the PostgreSQL documentation for more information about this
procedure.