database/postgres
1
0
Fork 0
mirror of https://github.com/postgres/postgres.git synced 2025-10-15 05:46:52 +03:00
Code Activity

Major overhaul of btree index code. Eliminate special BTP_CHAIN logic for

Browse Source 
duplicate keys by letting search go to the left rather than right when an
equal key is seen at an upper tree level.  Fix poor choice of page split
point (leading to insertion failures) that was forced by chaining logic.
Don't store leftmost key in non-leaf pages, since it's not necessary.
Don't create root page until something is first stored in the index, so an
unused index is now 8K not 16K.  (Doesn't seem to be as easy to get rid of
the metadata page, unfortunately.)  Massive cleanup of unreadable code,
fix poor, obsolete, and just plain wrong documentation and comments.
See src/backend/access/nbtree/README for the gory details.
This commit is contained in:
Tom Lane
2000-07-21 06:42:39 +00:00
parent c9537ca88f
commit 9e85183bfc
11 changed files with 1629 additions and 2859 deletions
Download Patch File Download Diff File Expand all files Collapse all files

54
src/backend/access/nbtree/nbtutils.c
View File

@@ -8,7 +8,7 @@
*
*
* IDENTIFICATION
* $Header: /cvsroot/pgsql/src/backend/access/nbtree/nbtutils.c,v 1.37 2000/05/30 04:24:33 tgl Exp $
* $Header: /cvsroot/pgsql/src/backend/access/nbtree/nbtutils.c,v 1.38 2000/07/21 06:42:33 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@@ -20,16 +20,13 @@
#include "access/nbtree.h"
#include "executor/execdebug.h"
extern int NIndexTupleProcessed;
/*
* _bt_mkscankey
* Build a scan key that contains comparison data from itup
* as well as comparator routines appropriate to the key datatypes.
*
* The result is intended for use with _bt_skeycmp() or _bt_compare(),
* although it could be used with _bt_itemcmp() or _bt_tuplecompare().
* The result is intended for use with _bt_compare().
*/
ScanKey
_bt_mkscankey(Relation rel, IndexTuple itup)
@@ -68,8 +65,9 @@ _bt_mkscankey(Relation rel, IndexTuple itup)
* Build a scan key that contains comparator routines appropriate to
* the key datatypes, but no comparison data.
*
* The result can be used with _bt_itemcmp() or _bt_tuplecompare(),
* but not with _bt_skeycmp() or _bt_compare().
* The result cannot be used with _bt_compare(). Currently this
* routine is only called by utils/sort/tuplesort.c, which has its
* own comparison routine.
*/
ScanKey
_bt_mkscankey_nodata(Relation rel)
@@ -114,7 +112,6 @@ _bt_freestack(BTStack stack)
{
ostack = stack;
stack = stack->bts_parent;
pfree(ostack->bts_btitem);
pfree(ostack);
}
}
@@ -331,55 +328,16 @@ _bt_formitem(IndexTuple itup)
Size tuplen;
extern Oid newoid();
/*
* see comments in btbuild
*
* if (itup->t_info & INDEX_NULL_MASK) elog(ERROR, "btree indices cannot
* include null keys");
*/
/* make a copy of the index tuple with room for the sequence number */
tuplen = IndexTupleSize(itup);
nbytes_btitem = tuplen + (sizeof(BTItemData) - sizeof(IndexTupleData));
btitem = (BTItem) palloc(nbytes_btitem);
memmove((char *) &(btitem->bti_itup), (char *) itup, tuplen);
memcpy((char *) &(btitem->bti_itup), (char *) itup, tuplen);
return btitem;
}
#ifdef NOT_USED
bool
_bt_checkqual(IndexScanDesc scan, IndexTuple itup)
{
BTScanOpaque so;
so = (BTScanOpaque) scan->opaque;
if (so->numberOfKeys > 0)
return (index_keytest(itup, RelationGetDescr(scan->relation),
so->numberOfKeys, so->keyData));
else
return true;
}
#endif
#ifdef NOT_USED
bool
_bt_checkforkeys(IndexScanDesc scan, IndexTuple itup, Size keysz)
{
BTScanOpaque so;
so = (BTScanOpaque) scan->opaque;
if (keysz > 0 && so->numberOfKeys >= keysz)
return (index_keytest(itup, RelationGetDescr(scan->relation),
keysz, so->keyData));
else
return true;
}
#endif
bool
_bt_checkkeys(IndexScanDesc scan, IndexTuple tuple, Size *keysok)
{