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First cut at recycling space in btree indexes. Still some rough edges

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to fix, but it seems to basically work...
This commit is contained in:
Tom Lane
2003-02-23 06:17:13 +00:00
parent 27854915b9
commit 88dc31e3f2
8 changed files with 745 additions and 32 deletions
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12
src/backend/storage/freespace/freespace.c
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@@ -8,7 +8,7 @@
* Portions Copyright (c) 1994, Regents of the University of California
*
* IDENTIFICATION
* $Header: /cvsroot/pgsql/src/backend/storage/freespace/freespace.c,v 1.14 2002/09/20 19:56:01 tgl Exp $
* $Header: /cvsroot/pgsql/src/backend/storage/freespace/freespace.c,v 1.15 2003/02/23 06:17:13 tgl Exp $
*
*
* NOTES:
@@ -681,7 +681,9 @@ free_chunk_chain(FSMChunk *fchunk)
* Look to see if a page with at least the specified amount of space is
* available in the given FSMRelation. If so, return its page number,
* and advance the nextPage counter so that the next inquiry will return
* a different page if possible. Return InvalidBlockNumber if no success.
* a different page if possible; also update the entry to show that the
* requested space is not available anymore. Return InvalidBlockNumber
* if no success.
*/
static BlockNumber
find_free_space(FSMRelation *fsmrel, Size spaceNeeded)
@@ -713,6 +715,12 @@ find_free_space(FSMRelation *fsmrel, Size spaceNeeded)
/* Check the next page */
if ((Size) curChunk->bytes[chunkRelIndex] >= spaceNeeded)
{
/*
* Found what we want --- adjust the entry. In theory we could
* delete the entry immediately if it drops below threshold,
* but it seems better to wait till we next need space.
*/
curChunk->bytes[chunkRelIndex] -= (ItemLength) spaceNeeded;
fsmrel->nextPage = pageIndex + 1;
return curChunk->pages[chunkRelIndex];
}