diff options
| author | Andres Freund | 2019-04-01 00:51:49 +0000 |
|---|---|---|
| committer | Andres Freund | 2019-04-01 01:37:57 +0000 |
| commit | bfbcad478f05794e5e7ea1339e62a1d258c99b6c (patch) | |
| tree | eec25ff67307f13fa7476d916ed04dc53da2c9b0 /src/include/nodes | |
| parent | 73c954d24896aeb05de0f81d75e891a858e439e9 (diff) | |
tableam: bitmap table scan.
This moves bitmap heap scan support to below an optional tableam
callback. It's optional as the whole concept of bitmap heapscans is
fairly block specific.
This basically moves the work previously done in bitgetpage() into the
new scan_bitmap_next_block callback, and the direct poking into the
buffer done in BitmapHeapNext() into the new scan_bitmap_next_tuple()
callback.
The abstraction is currently somewhat leaky because
nodeBitmapHeapscan.c's prefetching and visibilitymap based logic
remains - it's likely that we'll later have to move more into the
AM. But it's not trivial to do so without introducing a significant
amount of code duplication between the AMs, so that's a project for
later.
Note that now nodeBitmapHeapscan.c and the associated node types are a
bit misnamed. But it's not clear whether renaming wouldn't be a cure
worse than the disease. Either way, that'd be best done in a separate
commit.
Author: Andres Freund
Reviewed-By: Robert Haas (in an older version)
Discussion: https://postgr.es/m/20180703070645.wchpu5muyto5n647@alap3.anarazel.de
Diffstat (limited to 'src/include/nodes')
| -rw-r--r-- | src/include/nodes/execnodes.h | 4 | ||||
| -rw-r--r-- | src/include/nodes/tidbitmap.h | 2 |
2 files changed, 3 insertions, 3 deletions
diff --git a/src/include/nodes/execnodes.h b/src/include/nodes/execnodes.h index 437a191b458..5b4ea6c2355 100644 --- a/src/include/nodes/execnodes.h +++ b/src/include/nodes/execnodes.h @@ -1507,7 +1507,7 @@ typedef struct ParallelBitmapHeapState * tbmiterator iterator for scanning current pages * tbmres current-page data * can_skip_fetch can we potentially skip tuple fetches in this scan? - * skip_fetch are we skipping tuple fetches on this page? + * return_empty_tuples number of empty tuples to return * vmbuffer buffer for visibility-map lookups * pvmbuffer ditto, for prefetched pages * exact_pages total number of exact pages retrieved @@ -1531,7 +1531,7 @@ typedef struct BitmapHeapScanState TBMIterator *tbmiterator; TBMIterateResult *tbmres; bool can_skip_fetch; - bool skip_fetch; + int return_empty_tuples; Buffer vmbuffer; Buffer pvmbuffer; long exact_pages; diff --git a/src/include/nodes/tidbitmap.h b/src/include/nodes/tidbitmap.h index 2645085b344..6a7f3054a41 100644 --- a/src/include/nodes/tidbitmap.h +++ b/src/include/nodes/tidbitmap.h @@ -37,7 +37,7 @@ typedef struct TBMIterator TBMIterator; typedef struct TBMSharedIterator TBMSharedIterator; /* Result structure for tbm_iterate */ -typedef struct +typedef struct TBMIterateResult { BlockNumber blockno; /* page number containing tuples */ int ntuples; /* -1 indicates lossy result */ |