index 34990c5cea3f3605bc54966dc94bef2ea632f864..7cfb136763f6493b62641e2b087e986e53e604d4 100644 (file)
bool lowersizelimit;
ItemPointer scantid;
+ /*
+ * True if we already called bt_entry_unique_check() for the current
+ * item. This helps to avoid visiting the heap for keys, which are
+ * anyway presented only once and can't comprise a unique violation.
+ */
+ bool unique_checked = false;
+
CHECK_FOR_INTERRUPTS();
itemid = PageGetItemIdCareful(state, state->targetblock,
/*
* If the index is unique verify entries uniqueness by checking the
- * heap tuples visibility.
+ * heap tuples visibility. Immediately check posting tuples and
+ * tuples with repeated keys. Postpone check for keys, which have the
+ * first appearance.
*/
if (state->checkunique && state->indexinfo->ii_Unique &&
- P_ISLEAF(topaque) && !skey->anynullkeys)
+ P_ISLEAF(topaque) && !skey->anynullkeys &&
+ (BTreeTupleIsPosting(itup) || ItemPointerIsValid(lVis.tid)))
+ {
bt_entry_unique_check(state, itup, state->targetblock, offset,
&lVis);
+ unique_checked = true;
+ }
if (state->checkunique && state->indexinfo->ii_Unique &&
P_ISLEAF(topaque) && OffsetNumberNext(offset) <= max)
* data (whole index tuple or last posting in index tuple). Key
* containing null value does not violate unique constraint and
* treated as different to any other key.
+ *
+ * If the next key is the same as the previous one, do the
+ * bt_entry_unique_check() call if it was postponed.
*/
if (_bt_compare(state->rel, skey, state->target,
OffsetNumberNext(offset)) != 0 || skey->anynullkeys)
lVis.postingIndex = -1;
lVis.tid = NULL;
}
+ else if (!unique_checked)
+ {
+ bt_entry_unique_check(state, itup, state->targetblock, offset,
+ &lVis);
+ }
skey->scantid = scantid; /* Restore saved scan key state */
}
rightkey->scantid = NULL;
/* The first key on the next page is the same */
- if (_bt_compare(state->rel, rightkey, state->target, max) == 0 && !rightkey->anynullkeys)
+ if (_bt_compare(state->rel, rightkey, state->target, max) == 0 &&
+ !rightkey->anynullkeys)
{
Page rightpage;
+ /*
+ * Do the bt_entry_unique_check() call if it was
+ * postponed.
+ */
+ if (!unique_checked)
+ bt_entry_unique_check(state, itup, state->targetblock,
+ offset, &lVis);
+
elog(DEBUG2, "cross page equal keys");
rightpage = palloc_btree_page(state,
rightblock_number);