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Simplify a couple of pg_dump and psql \d queries about index constraints

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by joining to pg_constraint.conindid, instead of the former technique of
joining indirectly through pg_depend.  This is much more straightforward
and probably faster as well.  I had originally desisted from changing these
queries when conindid was added because I was worried about losing
performance, but if we join on conrelid as well as conindid then the index
on conrelid can be used when pg_constraint is large.
This commit is contained in:
Tom Lane
2010-03-11 04:36:43 +00:00
parent 4df5c6c719
commit e6555b436e
2 changed files with 30 additions and 36 deletions
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16
src/bin/pg_dump/pg_dump.c
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@@ -25,7 +25,7 @@
* http://archives.postgresql.org/pgsql-bugs/2010-02/msg00187.php
*
* IDENTIFICATION
* $PostgreSQL: pgsql/src/bin/pg_dump/pg_dump.c,v 1.577 2010/03/03 23:38:44 momjian Exp $
* $PostgreSQL: pgsql/src/bin/pg_dump/pg_dump.c,v 1.578 2010/03/11 04:36:43 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@@ -3956,6 +3956,11 @@ getIndexes(TableInfo tblinfo[], int numTables)
* that is related by an internal dependency link to the index. If we
* find one, create a CONSTRAINT entry linked to the INDEX entry. We
* assume an index won't have more than one internal dependency.
*
* As of 9.0 we don't need to look at pg_depend but can check for
* a match to pg_constraint.conindid. The check on conrelid is
* redundant but useful because that column is indexed while conindid
* is not.
*/
resetPQExpBuffer(query);
if (g_fout->remoteVersion >= 90000)
@@ -3975,13 +3980,10 @@ getIndexes(TableInfo tblinfo[], int numTables)
"array_to_string(t.reloptions, ', ') AS options "
"FROM pg_catalog.pg_index i "
"JOIN pg_catalog.pg_class t ON (t.oid = i.indexrelid) "
"LEFT JOIN pg_catalog.pg_depend d "
"ON (d.classid = t.tableoid "
"AND d.objid = t.oid "
"AND d.deptype = 'i') "
"LEFT JOIN pg_catalog.pg_constraint c "
"ON (d.refclassid = c.tableoid "
"AND d.refobjid = c.oid) "
"ON (i.indrelid = c.conrelid AND "
"i.indexrelid = c.conindid AND "
"c.contype IN ('p','u','x')) "
"WHERE i.indrelid = '%u'::pg_catalog.oid "
"ORDER BY indexname",
tbinfo->dobj.catId.oid);