diff options
Diffstat (limited to 'src/backend/access/heap/heapam.c')
| -rw-r--r-- | src/backend/access/heap/heapam.c | 22 |
1 files changed, 18 insertions, 4 deletions
diff --git a/src/backend/access/heap/heapam.c b/src/backend/access/heap/heapam.c index 8f671ac4342..43098f44422 100644 --- a/src/backend/access/heap/heapam.c +++ b/src/backend/access/heap/heapam.c @@ -272,6 +272,8 @@ initscan(HeapScanDesc scan, ScanKey key, bool is_rescan) scan->rs_startblock = 0; } + scan->rs_initblock = 0; + scan->rs_numblocks = InvalidBlockNumber; scan->rs_inited = false; scan->rs_ctup.t_data = NULL; ItemPointerSetInvalid(&scan->rs_ctup.t_self); @@ -297,6 +299,14 @@ initscan(HeapScanDesc scan, ScanKey key, bool is_rescan) pgstat_count_heap_scan(scan->rs_rd); } +void +heap_setscanlimits(HeapScanDesc scan, BlockNumber startBlk, BlockNumber numBlks) +{ + scan->rs_startblock = startBlk; + scan->rs_initblock = startBlk; + scan->rs_numblocks = numBlks; +} + /* * heapgetpage - subroutine for heapgettup() * @@ -637,7 +647,8 @@ heapgettup(HeapScanDesc scan, */ if (backward) { - finished = (page == scan->rs_startblock); + finished = (page == scan->rs_startblock) || + (scan->rs_numblocks != InvalidBlockNumber ? --scan->rs_numblocks <= 0 : false); if (page == 0) page = scan->rs_nblocks; page--; @@ -647,7 +658,8 @@ heapgettup(HeapScanDesc scan, page++; if (page >= scan->rs_nblocks) page = 0; - finished = (page == scan->rs_startblock); + finished = (page == scan->rs_startblock) || + (scan->rs_numblocks != InvalidBlockNumber ? --scan->rs_numblocks <= 0 : false); /* * Report our new scan position for synchronization purposes. We @@ -898,7 +910,8 @@ heapgettup_pagemode(HeapScanDesc scan, */ if (backward) { - finished = (page == scan->rs_startblock); + finished = (page == scan->rs_startblock) || + (scan->rs_numblocks != InvalidBlockNumber ? --scan->rs_numblocks <= 0 : false); if (page == 0) page = scan->rs_nblocks; page--; @@ -908,7 +921,8 @@ heapgettup_pagemode(HeapScanDesc scan, page++; if (page >= scan->rs_nblocks) page = 0; - finished = (page == scan->rs_startblock); + finished = (page == scan->rs_startblock) || + (scan->rs_numblocks != InvalidBlockNumber ? --scan->rs_numblocks <= 0 : false); /* * Report our new scan position for synchronization purposes. We |