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Redefine the lp_flags field of item pointers as having four states, rather

than two independent bits (one of which was never used in heap pages anyway,
or at least hadn't been in a very long time).  This gives us flexibility to
add the HOT notions of redirected and dead item pointers without requiring
anything so klugy as magic values of lp_off and lp_len.  The state values
are chosen so that for the states currently in use (pre-HOT) there is no
change in the physical representation.
This commit is contained in:
Tom Lane
2007-09-12 22:10:26 +00:00
parent eb0a7735ba
commit 6889303531
31 changed files with 278 additions and 185 deletions

View File

@ -8,7 +8,7 @@
*
*
* IDENTIFICATION
* $PostgreSQL: pgsql/src/backend/commands/sequence.c,v 1.144 2007/09/05 18:10:47 tgl Exp $
* $PostgreSQL: pgsql/src/backend/commands/sequence.c,v 1.145 2007/09/12 22:10:26 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@ -936,7 +936,7 @@ read_info(SeqTable elm, Relation rel, Buffer *buf)
RelationGetRelationName(rel), sm->magic);
lp = PageGetItemId(page, FirstOffsetNumber);
Assert(ItemIdIsUsed(lp));
Assert(ItemIdIsNormal(lp));
tuple.t_data = (HeapTupleHeader) PageGetItem((Page) page, lp);
seq = (Form_pg_sequence) GETSTRUCT(&tuple);
@ -1281,7 +1281,7 @@ seq_redo(XLogRecPtr lsn, XLogRecord *record)
itemsz = record->xl_len - sizeof(xl_seq_rec);
itemsz = MAXALIGN(itemsz);
if (PageAddItem(page, (Item) item, itemsz,
FirstOffsetNumber, LP_USED) == InvalidOffsetNumber)
FirstOffsetNumber, false) == InvalidOffsetNumber)
elog(PANIC, "seq_redo: failed to add item to page");
PageSetLSN(page, lsn);

View File

@ -7,7 +7,7 @@
* Portions Copyright (c) 1994, Regents of the University of California
*
* IDENTIFICATION
* $PostgreSQL: pgsql/src/backend/commands/trigger.c,v 1.218 2007/08/15 21:39:50 tgl Exp $
* $PostgreSQL: pgsql/src/backend/commands/trigger.c,v 1.219 2007/09/12 22:10:26 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@ -1826,7 +1826,7 @@ ltrmark:;
dp = (PageHeader) BufferGetPage(buffer);
lp = PageGetItemId(dp, ItemPointerGetOffsetNumber(tid));
Assert(ItemIdIsUsed(lp));
Assert(ItemIdIsNormal(lp));
tuple.t_data = (HeapTupleHeader) PageGetItem((Page) dp, lp);
tuple.t_len = ItemIdGetLength(lp);

View File

@ -13,7 +13,7 @@
*
*
* IDENTIFICATION
* $PostgreSQL: pgsql/src/backend/commands/vacuum.c,v 1.357 2007/09/08 20:31:14 tgl Exp $
* $PostgreSQL: pgsql/src/backend/commands/vacuum.c,v 1.358 2007/09/12 22:10:26 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@ -1522,7 +1522,7 @@ scan_heap(VRelStats *vacrelstats, Relation onerel,
/* mark it unused on the temp page */
lpp = PageGetItemId(tempPage, offnum);
lpp->lp_flags &= ~LP_USED;
ItemIdSetUnused(lpp);
vacpage->offsets[vacpage->offsets_free++] = offnum;
tups_vacuumed += 1;
@ -1558,7 +1558,7 @@ scan_heap(VRelStats *vacrelstats, Relation onerel,
{
/* Just use current available space */
vacpage->free = PageGetFreeSpaceWithFillFactor(onerel, page);
/* Need to reap the page if it has ~LP_USED line pointers */
/* Need to reap the page if it has LP_UNUSED line pointers */
do_reap = (vacpage->offsets_free > 0);
}
@ -2582,7 +2582,7 @@ repair_frag(VRelStats *vacrelstats, Relation onerel,
if (HeapTupleHeaderGetXvac(htup) != myXID)
elog(ERROR, "invalid XVAC in tuple header");
itemid->lp_flags &= ~LP_USED;
ItemIdSetUnused(itemid);
num_tuples++;
}
Assert(vacpage->offsets_free == num_tuples);
@ -2714,7 +2714,7 @@ move_chain_tuple(Relation rel,
newtup.t_data->t_infomask |= HEAP_MOVED_IN;
HeapTupleHeaderSetXvac(newtup.t_data, myXID);
newoff = PageAddItem(dst_page, (Item) newtup.t_data, tuple_len,
InvalidOffsetNumber, LP_USED);
InvalidOffsetNumber, false);
if (newoff == InvalidOffsetNumber)
elog(PANIC, "failed to add item with len = %lu to page %u while moving tuple chain",
(unsigned long) tuple_len, dst_vacpage->blkno);
@ -2819,7 +2819,7 @@ move_plain_tuple(Relation rel,
/* add tuple to the page */
newoff = PageAddItem(dst_page, (Item) newtup.t_data, tuple_len,
InvalidOffsetNumber, LP_USED);
InvalidOffsetNumber, false);
if (newoff == InvalidOffsetNumber)
elog(PANIC, "failed to add item with len = %lu to page %u (free space %lu, nusd %u, noff %u)",
(unsigned long) tuple_len,
@ -3033,7 +3033,7 @@ vacuum_page(Relation onerel, Buffer buffer, VacPage vacpage)
for (i = 0; i < vacpage->offsets_free; i++)
{
itemid = PageGetItemId(page, vacpage->offsets[i]);
itemid->lp_flags &= ~LP_USED;
ItemIdSetUnused(itemid);
}
uncnt = PageRepairFragmentation(page, unused);

View File

@ -36,7 +36,7 @@
*
*
* IDENTIFICATION
* $PostgreSQL: pgsql/src/backend/commands/vacuumlazy.c,v 1.94 2007/09/12 02:05:48 alvherre Exp $
* $PostgreSQL: pgsql/src/backend/commands/vacuumlazy.c,v 1.95 2007/09/12 22:10:26 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@ -642,7 +642,7 @@ lazy_vacuum_page(Relation onerel, BlockNumber blkno, Buffer buffer,
break; /* past end of tuples for this block */
toff = ItemPointerGetOffsetNumber(&vacrelstats->dead_tuples[tupindex]);
itemid = PageGetItemId(page, toff);
itemid->lp_flags &= ~LP_USED;
ItemIdSetUnused(itemid);
}
uncnt = PageRepairFragmentation(page, unused);