database/postgres
1
0
Fork 0
mirror of https://github.com/postgres/postgres.git synced 2025-07-08 11:42:09 +03:00
Code Activity

nbtree: Allocate new pages in separate function.

Browse Source 
Split nbtree's _bt_getbuf function is two: code that read locks or write
locks existing pages remains in _bt_getbuf, while code that deals with
allocating new pages is moved to a new, dedicated function called
_bt_allocbuf.  This simplifies most _bt_getbuf callers, since it is no
longer necessary for them to pass a heaprel argument.  Many of the
changes to nbtree from commit 61b313e4 can be reverted.  This minimizes
the divergence between HEAD/PostgreSQL 16 and earlier release branches.

_bt_allocbuf replaces the previous nbtree idiom of passing P_NEW to
_bt_getbuf.  There are only 3 affected call sites, all of which continue
to pass a heaprel for recovery conflict purposes.  Note that nbtree's
use of P_NEW was superficial; nbtree never actually relied on the P_NEW
code paths in bufmgr.c, so this change is strictly mechanical.

GiST already took the same approach; it has a dedicated function for
allocating new pages called gistNewBuffer().  That factor allowed commit
61b313e4 to make much more targeted changes to GiST.

Author: Peter Geoghegan <pg@bowt.ie>
Reviewed-By: Heikki Linnakangas <hlinnaka@iki.fi>
Discussion: https://postgr.es/m/CAH2-Wz=8Z9qY58bjm_7TAHgtW6RzZ5Ke62q5emdCEy9BAzwhmg@mail.gmail.com
This commit is contained in:
Peter Geoghegan
2023-06-10 14:08:25 -07:00
parent fe879ae3a8
commit d088ba5a5a
12 changed files with 271 additions and 257 deletions
Download Patch File Download Diff File Expand all files Collapse all files

7
src/backend/access/nbtree/nbtutils.c
View File

@ -87,7 +87,7 @@ static int _bt_keep_natts(Relation rel, IndexTuple lastleft,
* field themselves.
*/
BTScanInsert
_bt_mkscankey(Relation rel, Relation heaprel, IndexTuple itup)
_bt_mkscankey(Relation rel, IndexTuple itup)
{
BTScanInsert key;
ScanKey skey;
@ -112,7 +112,7 @@ _bt_mkscankey(Relation rel, Relation heaprel, IndexTuple itup)
key = palloc(offsetof(BTScanInsertData, scankeys) +
sizeof(ScanKeyData) * indnkeyatts);
if (itup)
_bt_metaversion(rel, heaprel, &key->heapkeyspace, &key->allequalimage);
_bt_metaversion(rel, &key->heapkeyspace, &key->allequalimage);
else
{
/* Utility statement callers can set these fields themselves */
@ -1761,8 +1761,7 @@ _bt_killitems(IndexScanDesc scan)
droppedpin = true;
/* Attempt to re-read the buffer, getting pin and lock. */
buf = _bt_getbuf(scan->indexRelation, scan->heapRelation,
so->currPos.currPage, BT_READ);
buf = _bt_getbuf(scan->indexRelation, so->currPos.currPage, BT_READ);
page = BufferGetPage(buf);
if (BufferGetLSNAtomic(buf) == so->currPos.lsn)