diff options
Diffstat (limited to 'src/backend/access/nbtree/nbtutils.c')
| -rw-r--r-- | src/backend/access/nbtree/nbtutils.c | 59 |
1 files changed, 59 insertions, 0 deletions
diff --git a/src/backend/access/nbtree/nbtutils.c b/src/backend/access/nbtree/nbtutils.c index 33ad8915f5a..50df5e0e5ba 100644 --- a/src/backend/access/nbtree/nbtutils.c +++ b/src/backend/access/nbtree/nbtutils.c @@ -595,6 +595,65 @@ _bt_advance_array_keys(IndexScanDesc scan, ScanDirection dir) return found; } +/* + * _bt_mark_array_keys() -- Handle array keys during btmarkpos + * + * Save the current state of the array keys as the "mark" position. + */ +void +_bt_mark_array_keys(IndexScanDesc scan) +{ + BTScanOpaque so = (BTScanOpaque) scan->opaque; + int i; + + for (i = 0; i < so->numArrayKeys; i++) + { + BTArrayKeyInfo *curArrayKey = &so->arrayKeys[i]; + + curArrayKey->mark_elem = curArrayKey->cur_elem; + } +} + +/* + * _bt_restore_array_keys() -- Handle array keys during btrestrpos + * + * Restore the array keys to where they were when the mark was set. + */ +void +_bt_restore_array_keys(IndexScanDesc scan) +{ + BTScanOpaque so = (BTScanOpaque) scan->opaque; + bool changed = false; + int i; + + /* Restore each array key to its position when the mark was set */ + for (i = 0; i < so->numArrayKeys; i++) + { + BTArrayKeyInfo *curArrayKey = &so->arrayKeys[i]; + ScanKey skey = &so->arrayKeyData[curArrayKey->scan_key]; + int mark_elem = curArrayKey->mark_elem; + + if (curArrayKey->cur_elem != mark_elem) + { + curArrayKey->cur_elem = mark_elem; + skey->sk_argument = curArrayKey->elem_values[mark_elem]; + changed = true; + } + } + + /* + * If we changed any keys, we must redo _bt_preprocess_keys. That might + * sound like overkill, but in cases with multiple keys per index column + * it seems necessary to do the full set of pushups. + */ + if (changed) + { + _bt_preprocess_keys(scan); + /* The mark should have been set on a consistent set of keys... */ + Assert(so->qual_ok); + } +} + /* * _bt_preprocess_keys() -- Preprocess scan keys |