Patch applied. Thanks.
---
Heikki Linnakangas wrote:
> Here's a patch that:
>
> Moves the logic to find a page with enough room from _bt_insertonpg to a
> new function, _bt_findinsertloc. It makes the code more readable, and
> simplifies the forthcoming Grouped Index Tuples patch.
>
> Also, the insert location within page used to be calculated twice for
> unique indexes, once in _bt_checkunique and second time in
> _bt_insertonpg. That's a waste of cycles, and this patch fixes that.
>
>
> I couldn't measure a difference with pgbench, but this micro-benchmark
> shows it:
>
> > psql postgres -c "CREATE TABLE inserttest (i int PRIMARY KEY);"
> > psql postgres -c "TRUNCATE inserttest; checkpoint;"; sync
> > time ~/pgsql.cvshead/bin/psql postgres -c "TRUNCATE inserttest;
> INSERT INTO inserttest SELECT a FROM generate_series(1,100) a;"
>
> Without patch:real0m7.260s
> With patch: real0m6.963s
>
> On my laptop, fsync=off, full_page_writes=off, checkpoint_segments = 10,
> to remove any other variables.
>
> It's not a huge difference, but it's worth having, and performance
> wasn't the main motivation of the patch anyway.
>
> --
>Heikki Linnakangas
>EnterpriseDB http://www.enterprisedb.com
[ text/x-patch is unsupported, treating like TEXT/PLAIN ]
> Index: src/backend/access/nbtree/nbtinsert.c
> ===
> RCS file:
> /home/hlinnaka/pgcvsrepository/pgsql/src/backend/access/nbtree/nbtinsert.c,v
> retrieving revision 1.152
> diff -c -r1.152 nbtinsert.c
> *** src/backend/access/nbtree/nbtinsert.c 21 Feb 2007 20:02:17 -
> 1.152
> --- src/backend/access/nbtree/nbtinsert.c 26 Feb 2007 09:37:16 -
> ***
> *** 46,58
> static Buffer _bt_newroot(Relation rel, Buffer lbuf, Buffer rbuf);
>
> static TransactionId _bt_check_unique(Relation rel, IndexTuple itup,
> ! Relation heapRel, Buffer buf,
>ScanKey itup_scankey);
> static void _bt_insertonpg(Relation rel, Buffer buf,
> BTStack stack,
> -int keysz, ScanKey scankey,
> IndexTuple itup,
> !OffsetNumber afteritem,
> bool split_only_page);
> static Buffer _bt_split(Relation rel, Buffer buf, OffsetNumber firstright,
> OffsetNumber newitemoff, Size newitemsz,
> --- 46,63
> static Buffer _bt_newroot(Relation rel, Buffer lbuf, Buffer rbuf);
>
> static TransactionId _bt_check_unique(Relation rel, IndexTuple itup,
> ! Relation heapRel, Buffer buf, OffsetNumber
> ioffset,
>ScanKey itup_scankey);
> + static void _bt_findinsertloc(Relation rel,
> + Buffer *bufptr,
> + OffsetNumber *offsetptr,
> + int keysz,
> + ScanKey scankey,
> + IndexTuple newtup);
> static void _bt_insertonpg(Relation rel, Buffer buf,
> BTStack stack,
> IndexTuple itup,
> !OffsetNumber newitemoff,
> bool split_only_page);
> static Buffer _bt_split(Relation rel, Buffer buf, OffsetNumber firstright,
> OffsetNumber newitemoff, Size newitemsz,
> ***
> *** 86,91
> --- 91,97
> ScanKey itup_scankey;
> BTStack stack;
> Buffer buf;
> + OffsetNumber offset;
>
> /* we need an insertion scan key to do our search, so build one */
> itup_scankey = _bt_mkscankey(rel, itup);
> ***
> *** 94,99
> --- 100,107
> /* find the first page containing this key */
> stack = _bt_search(rel, natts, itup_scankey, false, &buf, BT_WRITE);
>
> + offset = InvalidOffsetNumber;
> +
> /* trade in our read lock for a write lock */
> LockBuffer(buf, BUFFER_LOCK_UNLOCK);
> LockBuffer(buf, BT_WRITE);
> ***
> *** 128,134
> {
> TransactionId xwait;
>
> ! xwait = _bt_check_unique(rel, itup, heapRel, buf, itup_scankey);
>
> if (TransactionIdIsValid(xwait))
> {
> --- 136,143
> {
> TransactionId xwait;
>
> ! offset = _bt_binsrch(rel, buf, natts, itup_scankey, false);
> ! xwait = _bt_check_unique(rel, itup, heapRel, buf, offset,
> itup_scankey);
>
> if (TransactionIdIsValid(xwait))
> {
> ***
> *** 142,148
> }
>
> /* do the insertion */
> ! _bt_insertonpg(rel, buf, stack, natts, itup_scankey, itup, 0, false);
>
> /* be tidy */
> _bt_freestac
