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| author | Tom Lane <tgl@sss.pgh.pa.us> | 1999-07-30 00:44:23 +0000 |
|---|---|---|
| committer | Tom Lane <tgl@sss.pgh.pa.us> | 1999-07-30 00:44:23 +0000 |
| commit | 161be69544ef7e906626186866a23e14c9edaead (patch) | |
| tree | 05127c85f9cb13013b1b137d41fdcd889cc946cd /src | |
| parent | 12c51d9c6e84486b657b1486597d3a75707284b7 (diff) | |
| download | postgresql-161be69544ef7e906626186866a23e14c9edaead.tar.gz postgresql-161be69544ef7e906626186866a23e14c9edaead.zip | |
Update comments for create_indexscan_node().
Diffstat (limited to 'src')
| -rw-r--r-- | src/backend/optimizer/plan/createplan.c | 15 |
1 files changed, 9 insertions, 6 deletions
diff --git a/src/backend/optimizer/plan/createplan.c b/src/backend/optimizer/plan/createplan.c index a358308a468..11f98443b0f 100644 --- a/src/backend/optimizer/plan/createplan.c +++ b/src/backend/optimizer/plan/createplan.c @@ -7,7 +7,7 @@ * * * IDENTIFICATION - * $Header: /cvsroot/pgsql/src/backend/optimizer/plan/createplan.c,v 1.65 1999/07/29 02:48:05 tgl Exp $ + * $Header: /cvsroot/pgsql/src/backend/optimizer/plan/createplan.c,v 1.66 1999/07/30 00:44:23 tgl Exp $ * *------------------------------------------------------------------------- */ @@ -296,10 +296,13 @@ create_seqscan_node(Path *best_path, List *tlist, List *scan_clauses) * Returns a indexscan node for the base relation scanned by 'best_path' * with restriction clauses 'scan_clauses' and targetlist 'tlist'. * - * If an 'or' clause is to be used with this index, the indxqual field - * will contain a list of the 'or' clause arguments, e.g., the - * clause(OR a b c) will generate: ((a) (b) (c)). Otherwise, the - * indxqual will simply contain one conjunctive qualification: ((a)). + * The indexqual of the path contains a sublist of implicitly-ANDed qual + * conditions for each scan of the index(es); if there is more than one + * scan then the retrieved tuple sets are ORed together. The indexqual + * and indexid lists must have the same length, ie, the number of scans + * that will occur. Note it is possible for a qual condition sublist + * to be empty --- then no index restrictions will be applied during that + * scan. */ static IndexScan * create_indexscan_node(IndexPath *best_path, @@ -316,7 +319,7 @@ create_indexscan_node(IndexPath *best_path, /* there should be exactly one base rel involved... */ Assert(length(best_path->path.parent->relids) == 1); - /* check and see if any indices are lossy */ + /* check and see if any of the indices are lossy */ foreach(ixid, best_path->indexid) { HeapTuple indexTuple; |