diff options
| -rw-r--r-- | src/backend/executor/nodeIndexscan.c | 10 |
1 files changed, 8 insertions, 2 deletions
diff --git a/src/backend/executor/nodeIndexscan.c b/src/backend/executor/nodeIndexscan.c index 2db4015504e..59f54ee5cb4 100644 --- a/src/backend/executor/nodeIndexscan.c +++ b/src/backend/executor/nodeIndexscan.c @@ -8,7 +8,7 @@ * * * IDENTIFICATION - * $PostgreSQL: pgsql/src/backend/executor/nodeIndexscan.c,v 1.125 2008/01/01 19:45:49 momjian Exp $ + * $PostgreSQL: pgsql/src/backend/executor/nodeIndexscan.c,v 1.126 2008/03/18 03:54:52 tgl Exp $ * *------------------------------------------------------------------------- */ @@ -352,7 +352,13 @@ ExecIndexAdvanceArrayKeys(IndexArrayKeyInfo *arrayKeys, int numArrayKeys) bool found = false; int j; - for (j = 0; j < numArrayKeys; j++) + /* + * Note we advance the rightmost array key most quickly, since it will + * correspond to the lowest-order index column among the available + * qualifications. This is hypothesized to result in better locality + * of access in the index. + */ + for (j = numArrayKeys - 1; j >= 0; j--) { ScanKey scan_key = arrayKeys[j].scan_key; int next_elem = arrayKeys[j].next_elem; |