database/postgres
1
0
Fork 0
mirror of https://github.com/postgres/postgres.git synced 2025-07-17 06:41:09 +03:00
Code Activity

Patch VACUUM problem with moving chain of update tuples when source

Browse Source 
and destination of a tuple lie on the same page.
This commit is contained in:
Tom Lane
2000-10-17 01:39:56 +00:00
parent c3bbbb1dcc
commit b611c38282
1 changed files with 56 additions and 22 deletions
Download Patch File Download Diff File Expand all files Collapse all files

76
src/backend/commands/vacuum.c
View File

@ -8,7 +8,7 @@
*
*
* IDENTIFICATION
* $Header: /cvsroot/pgsql/src/backend/commands/vacuum.c,v 1.148.2.1 2000/09/19 21:01:04 tgl Exp $
* $Header: /cvsroot/pgsql/src/backend/commands/vacuum.c,v 1.148.2.2 2000/10/17 01:39:56 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@ -815,6 +815,7 @@ vc_scanheap(VRelStats *vacrelstats, Relation onerel,
tuple.t_data->t_cmin))
{
tuple.t_data->t_infomask |= HEAP_XMIN_INVALID;
pgchanged = true;
tupgone = true;
}
else
@ -829,6 +830,7 @@ vc_scanheap(VRelStats *vacrelstats, Relation onerel,
tuple.t_data->t_cmin))
{
tuple.t_data->t_infomask |= HEAP_XMIN_INVALID;
pgchanged = true;
tupgone = true;
}
else
@ -876,8 +878,10 @@ vc_scanheap(VRelStats *vacrelstats, Relation onerel,
{
if (tuple.t_data->t_infomask & HEAP_MARKED_FOR_UPDATE)
{
pgchanged = true;
tuple.t_data->t_infomask |= HEAP_XMAX_INVALID;
tuple.t_data->t_infomask &=
~(HEAP_XMAX_COMMITTED | HEAP_MARKED_FOR_UPDATE);
pgchanged = true;
}
else
tupgone = true;
@ -892,6 +896,8 @@ vc_scanheap(VRelStats *vacrelstats, Relation onerel,
if (tuple.t_data->t_infomask & HEAP_MARKED_FOR_UPDATE)
{
tuple.t_data->t_infomask |= HEAP_XMAX_INVALID;
tuple.t_data->t_infomask &=
~(HEAP_XMAX_COMMITTED | HEAP_MARKED_FOR_UPDATE);
pgchanged = true;
}
else
@ -905,6 +911,8 @@ vc_scanheap(VRelStats *vacrelstats, Relation onerel,
* from crashed process. - vadim 06/02/97
*/
tuple.t_data->t_infomask |= HEAP_XMAX_INVALID;
tuple.t_data->t_infomask &=
~(HEAP_XMAX_COMMITTED | HEAP_MARKED_FOR_UPDATE);
pgchanged = true;
}
else
@ -964,6 +972,14 @@ vc_scanheap(VRelStats *vacrelstats, Relation onerel,
{
ItemId lpp;
/*
* Here we are building a temporary copy of the page with
* dead tuples removed. Below we will apply
* PageRepairFragmentation to the copy, so that we can
* determine how much space will be available after
* removal of dead tuples. But note we are NOT changing
* the real page yet...
*/
if (tempPage == (Page) NULL)
{
Size pageSize;
@ -973,14 +989,12 @@ vc_scanheap(VRelStats *vacrelstats, Relation onerel,
memmove(tempPage, page, pageSize);
}
/* mark it unused on the temp page */
lpp = &(((PageHeader) tempPage)->pd_linp[offnum - 1]);
/* mark it unused */
lpp->lp_flags &= ~LP_USED;
vpc->vpd_offsets[vpc->vpd_offsets_free++] = offnum;
tups_vacuumed++;
}
else
{
@ -1548,20 +1562,45 @@ vc_repair_frag(VRelStats *vacrelstats, Relation onerel,
tuple.t_datamcxt = NULL;
tuple.t_data = (HeapTupleHeader) PageGetItem(Cpage, Citemid);
tuple_len = tuple.t_len = ItemIdGetLength(Citemid);
/* Get page to move in */
/*
* make a copy of the source tuple, and then mark the
* source tuple MOVED_OFF.
*/
heap_copytuple_with_tuple(&tuple, &newtup);
RelationInvalidateHeapTuple(onerel, &tuple);
TransactionIdStore(myXID, (TransactionId *) &(tuple.t_data->t_cmin));
tuple.t_data->t_infomask &=
~(HEAP_XMIN_COMMITTED | HEAP_XMIN_INVALID | HEAP_MOVED_IN);
tuple.t_data->t_infomask |= HEAP_MOVED_OFF;
/* Get page to move to */
cur_buffer = ReadBuffer(onerel, destvpd->vpd_blkno);
/*
* We should LockBuffer(cur_buffer) but don't, at the
* moment. If you'll do LockBuffer then UNLOCK it
* before index_insert: unique btree-s call heap_fetch
* to get t_infomask of inserted heap tuple !!!
* moment. This should be safe enough, since we have
* exclusive lock on the whole relation.
* If you'll do LockBuffer then UNLOCK it before
* index_insert: unique btree-s call heap_fetch to get
* t_infomask of inserted heap tuple !!!
*/
ToPage = BufferGetPage(cur_buffer);
/*
* If this page was not used before - clean it.
*
* NOTE: a nasty bug used to lurk here. It is possible
* for the source and destination pages to be the same
* (since this tuple-chain member can be on a page lower
* than the one we're currently processing in the outer
* loop). If that's true, then after vc_vacpage() the
* source tuple will have been moved, and tuple.t_data
* will be pointing at garbage. Therefore we must do
* everything that uses tuple.t_data BEFORE this step!!
*
* This path is different from the other callers of
* vc_vacpage, because we have already incremented the
* vpd's vpd_offsets_used field to account for the
@ -1579,8 +1618,11 @@ vc_repair_frag(VRelStats *vacrelstats, Relation onerel,
vc_vacpage(ToPage, destvpd);
destvpd->vpd_offsets_used = sv_offsets_used;
}
heap_copytuple_with_tuple(&tuple, &newtup);
RelationInvalidateHeapTuple(onerel, &tuple);
/*
* Update the state of the copied tuple, and store it
* on the destination page.
*/
TransactionIdStore(myXID, (TransactionId *) &(newtup.t_data->t_cmin));
newtup.t_data->t_infomask &=
~(HEAP_XMIN_COMMITTED | HEAP_XMIN_INVALID | HEAP_MOVED_OFF);
@ -1601,8 +1643,8 @@ vc_repair_frag(VRelStats *vacrelstats, Relation onerel,
last_move_dest_block = destvpd->vpd_blkno;
/*
* Set t_ctid pointing to itself for last tuple in
* chain and to next tuple in chain otherwise.
* Set new tuple's t_ctid pointing to itself for last
* tuple in chain, and to next tuple in chain otherwise.
*/
if (!ItemPointerIsValid(&Ctid))
newtup.t_data->t_ctid = newtup.t_self;
@ -1610,11 +1652,6 @@ vc_repair_frag(VRelStats *vacrelstats, Relation onerel,
newtup.t_data->t_ctid = Ctid;
Ctid = newtup.t_self;
TransactionIdStore(myXID, (TransactionId *) &(tuple.t_data->t_cmin));
tuple.t_data->t_infomask &=
~(HEAP_XMIN_COMMITTED | HEAP_XMIN_INVALID | HEAP_MOVED_IN);
tuple.t_data->t_infomask |= HEAP_MOVED_OFF;
num_moved++;
/*
@ -1648,9 +1685,6 @@ vc_repair_frag(VRelStats *vacrelstats, Relation onerel,
}
}
WriteBuffer(cur_buffer);
if (Cbuf == buf)
ReleaseBuffer(Cbuf);
else
WriteBuffer(Cbuf);
}
cur_buffer = InvalidBuffer;