diff options
| author | Tom Lane <tgl@sss.pgh.pa.us> | 2003-01-20 18:55:07 +0000 |
|---|---|---|
| committer | Tom Lane <tgl@sss.pgh.pa.us> | 2003-01-20 18:55:07 +0000 |
| commit | bdfbfde1b168b3332c4cdac34ac86a80aaf4d442 (patch) | |
| tree | f35bf1af04733069f3a6b0a2698ac10dbd6544ed /doc/src | |
| parent | be2b660ecd5ca205570825633e7b8479379ddc64 (diff) | |
IN clauses appearing at top level of WHERE can now be handled as joins.
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.
Diffstat (limited to 'doc/src')
| -rw-r--r-- | doc/src/sgml/release.sgml | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/doc/src/sgml/release.sgml b/doc/src/sgml/release.sgml index 77fed8d8b02..2911e1828f9 100644 --- a/doc/src/sgml/release.sgml +++ b/doc/src/sgml/release.sgml @@ -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 |