Tom Lane 4767bc8ff2 Improve statistics estimation to make some use of DISTINCT in sub-queries. ... Formerly, we just punted when trying to estimate stats for variables coming out of sub-queries using DISTINCT, on the grounds that whatever stats we might have for underlying table columns would be inapplicable. But if the sub-query has only one DISTINCT column, we can consider its output variable as being unique, which is useful information all by itself. The scope of this improvement is pretty narrow, but it costs nearly nothing, so we might as well do it. Per discussion with Andres Freund. This patch differs from the draft I submitted yesterday in updating various comments about vardata.isunique (to reflect its extended meaning) and in tweaking the interaction with security_barrier views. There does not seem to be a reason why we can't use this sort of knowledge even when the sub-query is such a view.		2012-02-16 17:34:00 -05:00
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access	Assorted comment fixes, mostly just typos, but some obsolete statements.	2012-01-29 19:23:56 -05:00
bootstrap	Update copyright notices for year 2012.	2012-01-01 18:01:58 -05:00
catalog	Preserve column names in the execution-time tupledesc for a RowExpr.	2012-02-14 17:34:56 -05:00
commands	Add TIMING option to EXPLAIN, to allow eliminating of timing overhead.	2012-02-07 11:23:04 -05:00
datatype	Update copyright notices for year 2012.	2012-01-01 18:01:58 -05:00
executor	Preserve column names in the execution-time tupledesc for a RowExpr.	2012-02-14 17:34:56 -05:00
foreign	Update copyright notices for year 2012.	2012-01-01 18:01:58 -05:00
lib	Update copyright notices for year 2012.	2012-01-01 18:01:58 -05:00
libpq	Update copyright notices for year 2012.	2012-01-01 18:01:58 -05:00
mb	Update copyright notices for year 2012.	2012-01-01 18:01:58 -05:00
nodes	Preserve column names in the execution-time tupledesc for a RowExpr.	2012-02-14 17:34:56 -05:00
optimizer	Preserve column names in the execution-time tupledesc for a RowExpr.	2012-02-14 17:34:56 -05:00
parser	Allow LEAKPROOF functions for better performance of security views.	2012-02-13 22:21:14 -05:00
port	Support for building with MS Visual Studio 2010.	2012-01-03 08:44:26 -05:00
portability	Update copyright notices for year 2012.	2012-01-01 18:01:58 -05:00
postmaster	Update copyright notices for year 2012.	2012-01-01 18:01:58 -05:00
regex	Teach regular expression operators to honor collations.	2011-04-10 18:03:09 -04:00
replication	Various minor comments changes from bgwriter to checkpointer.	2012-01-30 14:34:25 +00:00
rewrite	Update copyright notices for year 2012.	2012-01-01 18:01:58 -05:00
snowball	Update copyright notices for year 2012.	2012-01-01 18:01:58 -05:00
storage	Rename LWLockWaitUntilFree to LWLockAcquireOrWait.	2012-02-08 09:17:13 +02:00
tcop	Update copyright notices for year 2012.	2012-01-01 18:01:58 -05:00
tsearch	Update copyright notices for year 2012.	2012-01-01 18:01:58 -05:00
utils	Improve statistics estimation to make some use of DISTINCT in sub-queries.	2012-02-16 17:34:00 -05:00
.gitignore	Convert cvsignore to gitignore, and add .gitignore for build targets.	2010-09-22 12:57:04 +02:00
c.h	Update copyright notices for year 2012.	2012-01-01 18:01:58 -05:00
fmgr.h	Update copyright notices for year 2012.	2012-01-01 18:01:58 -05:00
funcapi.h	Update copyright notices for year 2012.	2012-01-01 18:01:58 -05:00
getaddrinfo.h	Update copyright notices for year 2012.	2012-01-01 18:01:58 -05:00
getopt_long.h	Update copyright notices for year 2012.	2012-01-01 18:01:58 -05:00
Makefile	Fix server header file installation with vpath builds	2011-11-10 20:52:54 +02:00
miscadmin.h	Update copyright notices for year 2012.	2012-01-01 18:01:58 -05:00
pg_config_manual.h	Use LWSYNC in place of SYNC/ISYNC in PPC spinlocks, where possible.	2012-01-02 00:02:02 -05:00
pg_config.h.in	Support fls().	2012-02-07 13:45:46 -05:00
pg_config.h.win32	Remove support for on_exit()	2011-12-27 20:57:59 +02:00
pg_trace.h	Update copyright notices for year 2012.	2012-01-01 18:01:58 -05:00
pgstat.h	Add deadlock counter to pg_stat_database	2012-01-26 15:58:19 +01:00
pgtime.h	Update copyright notices for year 2012.	2012-01-01 18:01:58 -05:00
port.h	Support fls().	2012-02-07 13:45:46 -05:00
postgres_ext.h	Remove cvs keywords from all files.	2010-09-20 22:08:53 +02:00
postgres_fe.h	Update copyright notices for year 2012.	2012-01-01 18:01:58 -05:00
postgres.h	Update copyright notices for year 2012.	2012-01-01 18:01:58 -05:00
rusagestub.h	Update copyright notices for year 2012.	2012-01-01 18:01:58 -05:00
windowapi.h	Update copyright notices for year 2012.	2012-01-01 18:01:58 -05:00