diff options
Diffstat (limited to 'src/include/access/relscan.h')
| -rw-r--r-- | src/include/access/relscan.h | 39 |
1 files changed, 16 insertions, 23 deletions
diff --git a/src/include/access/relscan.h b/src/include/access/relscan.h index b97b52979e4..8bfb514b1e4 100644 --- a/src/include/access/relscan.h +++ b/src/include/access/relscan.h @@ -7,7 +7,7 @@ * Portions Copyright (c) 1996-2001, PostgreSQL Global Development Group * Portions Copyright (c) 1994, Regents of the University of California * - * $Id: relscan.h,v 1.20 2001/01/24 19:43:19 momjian Exp $ + * $Id: relscan.h,v 1.21 2001/06/09 18:16:59 tgl Exp $ * *------------------------------------------------------------------------- */ @@ -16,25 +16,16 @@ #include "utils/tqual.h" -typedef ItemPointerData MarkData; typedef struct HeapScanDescData { Relation rs_rd; /* pointer to relation descriptor */ - HeapTupleData rs_ptup; /* previous tuple in scan */ - HeapTupleData rs_ctup; /* current tuple in scan */ - HeapTupleData rs_ntup; /* next tuple in scan */ - Buffer rs_pbuf; /* previous buffer in scan */ - Buffer rs_cbuf; /* current buffer in scan */ - Buffer rs_nbuf; /* next buffer in scan */ - ItemPointerData rs_mptid; /* marked previous tid */ - ItemPointerData rs_mctid; /* marked current tid */ - ItemPointerData rs_mntid; /* marked next tid */ - ItemPointerData rs_mcd; /* marked current delta XXX ??? */ + HeapTupleData rs_ctup; /* current tuple in scan, if any */ + Buffer rs_cbuf; /* current buffer in scan, if any */ + /* NB: if rs_cbuf is not InvalidBuffer, we hold a pin on that buffer */ + ItemPointerData rs_mctid; /* marked tid, if any */ Snapshot rs_snapshot; /* snapshot to see */ - bool rs_atend; /* restart scan at end? */ - uint16 rs_cdelta; /* current delta in chain */ - uint16 rs_nkeys; /* number of attributes in keys */ + uint16 rs_nkeys; /* number of scan keys to select tuples */ ScanKey rs_key; /* key descriptors */ } HeapScanDescData; @@ -43,22 +34,24 @@ typedef HeapScanDescData *HeapScanDesc; typedef struct IndexScanDescData { Relation relation; /* relation descriptor */ - void *opaque; /* am-specific slot */ - ItemPointerData previousItemData; /* previous index pointer */ + void *opaque; /* access-method-specific info */ ItemPointerData currentItemData; /* current index pointer */ - ItemPointerData nextItemData; /* next index pointer */ - MarkData previousMarkData; /* marked previous pointer */ - MarkData currentMarkData;/* marked current pointer */ - MarkData nextMarkData; /* marked next pointer */ + ItemPointerData currentMarkData; /* marked current pointer */ uint8 flags; /* scan position flags */ bool scanFromEnd; /* restart scan at end? */ - uint16 numberOfKeys; /* number of key attributes */ - ScanKey keyData; /* key descriptor */ + uint16 numberOfKeys; /* number of scan keys to select tuples */ + ScanKey keyData; /* key descriptors */ FmgrInfo fn_getnext; /* cached lookup info for am's getnext fn */ } IndexScanDescData; typedef IndexScanDescData *IndexScanDesc; +/* IndexScanDesc flag bits (none of these are actually used currently) */ +#define ScanUnmarked 0x01 +#define ScanUncheckedPrevious 0x02 +#define ScanUncheckedNext 0x04 + + /* ---------------- * IndexScanDescPtr is used in the executor where we have to * keep track of several index scans when using several indices |