database/postgres
1
0
Fork 0
mirror of https://github.com/postgres/postgres.git synced 2025-07-28 23:42:10 +03:00
Code Activity

IN clauses appearing at top level of WHERE can now be handled as joins.

Browse Source 
There are two implementation techniques: the executor understands a new
JOIN_IN jointype, which emits at most one matching row per left-hand row,
or the result of the IN's sub-select can be fed through a DISTINCT filter
and then joined as an ordinary relation.
Along the way, some minor code cleanup in the optimizer; notably, break
out most of the jointree-rearrangement preprocessing in planner.c and
put it in a new file prep/prepjointree.c.
This commit is contained in:
Tom Lane
2003-01-20 18:55:07 +00:00
parent be2b660ecd
commit bdfbfde1b1
47 changed files with 2075 additions and 875 deletions
Download Patch File Download Diff File Expand all files Collapse all files

3
doc/src/sgml/release.sgml
View File

@ -1,5 +1,5 @@
<!--
$Header: /cvsroot/pgsql/doc/src/sgml/release.sgml,v 1.178 2003/01/11 21:02:49 momjian Exp $
$Header: /cvsroot/pgsql/doc/src/sgml/release.sgml,v 1.179 2003/01/20 18:54:44 tgl Exp $
-->
<appendix id="release">
@ -24,6 +24,7 @@ CDATA means the content is "SGML-free", so you can write without
worries about funny characters.
-->
<literallayout><![CDATA[
Performance of "foo IN (SELECT ...)" queries has been considerably improved
FETCH 0 now re-fetches cursor's current row, per SQL spec
Revised executor state representation; plan trees are read-only to executor now
Information schema