diff options
| -rw-r--r-- | src/backend/access/gin/ginget.c | 55 |
1 files changed, 32 insertions, 23 deletions
diff --git a/src/backend/access/gin/ginget.c b/src/backend/access/gin/ginget.c index dfc3dc48c80..fda19cf4e69 100644 --- a/src/backend/access/gin/ginget.c +++ b/src/backend/access/gin/ginget.c @@ -729,11 +729,18 @@ entryGetItem(GinState *ginstate, GinScanEntry entry, /* A bitmap result */ BlockNumber advancePastBlk = GinItemPointerGetBlockNumber(&advancePast); OffsetNumber advancePastOff = GinItemPointerGetOffsetNumber(&advancePast); + bool gotitem = false; do { - if (entry->matchResult == NULL || - entry->offset >= entry->matchResult->ntuples) + /* + * If we've exhausted all items on this block, move to next block + * in the bitmap. + */ + while (entry->matchResult == NULL || + (entry->matchResult->ntuples >= 0 && + entry->offset >= entry->matchResult->ntuples) || + entry->matchResult->blockno < advancePastBlk) { entry->matchResult = tbm_iterate(entry->matchIterator); @@ -747,18 +754,6 @@ entryGetItem(GinState *ginstate, GinScanEntry entry, } /* - * If all the matches on this page are <= advancePast, skip - * to next page. - */ - if (entry->matchResult->blockno < advancePastBlk || - (entry->matchResult->blockno == advancePastBlk && - entry->matchResult->offsets[entry->offset] <= advancePastOff)) - { - entry->offset = entry->matchResult->ntuples; - continue; - } - - /* * Reset counter to the beginning of entry->matchResult. Note: * entry->offset is still greater than matchResult->ntuples if * matchResult is lossy. So, on next call we will get next @@ -766,30 +761,43 @@ entryGetItem(GinState *ginstate, GinScanEntry entry, */ entry->offset = 0; } + if (entry->isFinished) + break; + /* + * We're now on the first page after advancePast which has any + * items on it. If it's a lossy result, return that. + */ if (entry->matchResult->ntuples < 0) { - /* - * lossy result, so we need to check the whole page - */ ItemPointerSetLossyPage(&entry->curItem, entry->matchResult->blockno); /* * We might as well fall out of the loop; we could not * estimate number of results on this page to support correct - * reducing of result even if it's enabled + * reducing of result even if it's enabled. */ + gotitem = true; break; } - + /* + * Not a lossy page. Skip over any offsets <= advancePast, and + * return that. + */ if (entry->matchResult->blockno == advancePastBlk) { /* - * Skip to the right offset on this page. We already checked - * in above loop that there is at least one item > advancePast - * on the page. + * First, do a quick check against the last offset on the page. + * If that's > advancePast, so are all the other offsets. */ + if (entry->matchResult->offsets[entry->matchResult->ntuples - 1] <= advancePastOff) + { + entry->offset = entry->matchResult->ntuples; + continue; + } + + /* Otherwise scan to find the first item > advancePast */ while (entry->matchResult->offsets[entry->offset] <= advancePastOff) entry->offset++; } @@ -798,7 +806,8 @@ entryGetItem(GinState *ginstate, GinScanEntry entry, entry->matchResult->blockno, entry->matchResult->offsets[entry->offset]); entry->offset++; - } while (entry->reduceResult == TRUE && dropItem(entry)); + gotitem = true; + } while (!gotitem || (entry->reduceResult == TRUE && dropItem(entry))); } else if (!BufferIsValid(entry->buffer)) { |