postgresql/contrib
Tom Lane 76f965ff1f Improve handling of collations in contrib/postgres_fdw.
If we have a local Var of say varchar type with default collation, and
we apply a RelabelType to convert that to text with default collation, we
don't want to consider that as creating an FDW_COLLATE_UNSAFE situation.
It should be okay to compare that to a remote Var, so long as the remote
Var determines the comparison collation.  (When we actually ship such an
expression to the remote side, the local Var would become a Param with
default collation, meaning the remote Var would in fact control the
comparison collation, because non-default implicit collation overrides
default implicit collation in parse_collate.c.)  To fix, be more precise
about what FDW_COLLATE_NONE means: it applies either to a noncollatable
data type or to a collatable type with default collation, if that collation
can't be traced to a remote Var.  (When it can, FDW_COLLATE_SAFE is
appropriate.)  We were essentially using that interpretation already at
the Var/Const/Param level, but we weren't bubbling it up properly.

An alternative fix would be to introduce a separate FDW_COLLATE_DEFAULT
value to describe the second situation, but that would add more code
without changing the actual behavior, so it didn't seem worthwhile.

Also, since we're clarifying the rule to be that we care about whether
operator/function input collations match, there seems no need to fail
immediately upon seeing a Const/Param/non-foreign-Var with nondefault
collation.  We only have to reject if it appears in a collation-sensitive
context (for example, "var IS NOT NULL" is perfectly safe from a collation
standpoint, whatever collation the var has).  So just set the state to
UNSAFE rather than failing immediately.

Per report from Jeevan Chalke.  This essentially corrects some sloppy
thinking in commit ed3ddf918b, so back-patch
to 9.3 where that logic appeared.
2015-09-24 12:47:29 -04:00
..
adminpack Update copyright for 2015 2015-01-06 11:43:47 -05:00
auth_delay Add file version information to most installed Windows binaries. 2014-07-14 14:07:52 -04:00
auto_explain Rearrange explain.c's API so callers need not embed sizeof(ExplainState). 2015-01-15 13:39:33 -05:00
btree_gin pgindent run for 9.5 2015-05-23 21:35:49 -04:00
btree_gist Fix misc typos. 2015-09-05 11:35:49 +03:00
chkpass Avoid returning undefined bytes in chkpass_in(). 2015-02-14 12:20:56 -05:00
citext Fix incorrect declaration of citext's regexp_matches() functions. 2015-05-05 15:51:22 -04:00
cube Fix misc typos. 2015-09-05 11:35:49 +03:00
dblink Rearrange the handling of error context reports. 2015-09-05 11:58:33 -04:00
dict_int Update copyright for 2015 2015-01-06 11:43:47 -05:00
dict_xsyn Update copyright for 2015 2015-01-06 11:43:47 -05:00
earthdistance Improve speed of make check-world 2015-04-23 08:59:52 -04:00
file_fdw TABLESAMPLE, SQL Standard and extensible 2015-05-15 14:37:10 -04:00
fuzzystrmatch pgindent run for 9.5 2015-05-23 21:35:49 -04:00
hstore pgindent run for 9.5 2015-05-23 21:35:49 -04:00
hstore_plperl Rearrange the handling of error context reports. 2015-09-05 11:58:33 -04:00
hstore_plpython Rearrange the handling of error context reports. 2015-09-05 11:58:33 -04:00
intagg Fix typos in some error messages thrown by extension scripts when fed to psql. 2014-08-25 18:30:37 +02:00
intarray Add selectivity estimation functions for intarray operators. 2015-07-21 20:59:24 +03:00
isn contrib/isn now needs a .gitignore file. 2015-08-02 23:57:32 -04:00
lo Fix typos in some error messages thrown by extension scripts when fed to psql. 2014-08-25 18:30:37 +02:00
ltree pgindent run for 9.5 2015-05-23 21:35:49 -04:00
ltree_plpython Rearrange the handling of error context reports. 2015-09-05 11:58:33 -04:00
oid2name Add file version information to most installed Windows binaries. 2014-07-14 14:07:52 -04:00
pageinspect Use materialize SRF mode in brin_page_items 2015-08-13 13:02:10 -03:00
passwordcheck Update copyright for 2015 2015-01-06 11:43:47 -05:00
pg_buffercache pgindent run for 9.5 2015-05-23 21:35:49 -04:00
pg_freespacemap Fix typos in some error messages thrown by extension scripts when fed to psql. 2014-08-25 18:30:37 +02:00
pg_prewarm Update copyright for 2015 2015-01-06 11:43:47 -05:00
pg_standby Don't use function definitions looking like old-style ones. 2015-08-15 17:25:00 +02:00
pg_stat_statements Redesign tablesample method API, and do extensive code review. 2015-07-25 14:39:00 -04:00
pg_trgm This supports the triconsistent function for pg_trgm GIN opclass 2015-07-20 18:18:48 +03:00
pgcrypto pgindent run for 9.5 2015-05-23 21:35:49 -04:00
pgrowlocks Optimize locking a tuple already locked by another subxact 2015-04-10 13:47:15 -03:00
pgstattuple Prevent pgstattuple() from reporting BRIN as unknown index. 2015-07-14 22:36:51 +09:00
postgres_fdw Improve handling of collations in contrib/postgres_fdw. 2015-09-24 12:47:29 -04:00
seg Move strategy numbers to include/access/stratnum.h 2015-05-15 17:03:16 -03:00
sepgsql Adjust sepgsql regression output for recent error context change 2015-09-06 11:25:36 -07:00
spi Collection of typo fixes. 2015-05-20 16:56:22 +03:00
sslinfo Fix error message wording in previous sslinfo commit 2015-09-08 11:10:20 -03:00
start-scripts Fix typo in linux startup script. 2015-04-26 09:43:15 -04:00
tablefunc Fix a number of places that produced XX000 errors in the regression tests. 2015-08-02 23:49:19 -04:00
tcn Update copyright for 2015 2015-01-06 11:43:47 -05:00
test_decoding test_decoding: Protect against rare spurious test failures. 2015-09-22 15:39:46 +02:00
tsearch2 Add an optional missing_ok argument to SQL function current_setting(). 2015-07-02 16:41:07 -04:00
tsm_system_rows Redesign tablesample method API, and do extensive code review. 2015-07-25 14:39:00 -04:00
tsm_system_time Some platforms now need contrib/tsm_system_time to be linked with libm. 2015-07-25 16:37:12 -04:00
unaccent Make unaccent handle all diacritics known to Unicode, and expand ligatures correctly 2015-09-04 12:51:53 +03:00
uuid-ossp Update copyright for 2015 2015-01-06 11:43:47 -05:00
vacuumlo vacuumlo: Avoid unlikely memory leak. 2015-01-14 15:14:20 -05:00
xml2 Replace a bunch more uses of strncpy() with safer coding. 2015-01-24 13:05:42 -05:00
Makefile Finish removing pg_audit 2015-05-28 12:48:25 -04:00
README Rename 'gmake' to 'make' in docs and recommended commands 2014-02-12 17:29:19 -05:00
contrib-global.mk Remove cvs keywords from all files. 2010-09-20 22:08:53 +02:00

README

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.