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Improved logic for updating HNSW insert page

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This commit is contained in:
Andrew Kane
2023-08-11 13:24:56 -07:00
parent daef83a112
commit ae5de26893
2 changed files with 20 additions and 12 deletions
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28
src/hnswinsert.c
View File

@@ -34,7 +34,7 @@ GetInsertPage(Relation index)
* Check for a free offset
*/
static bool
HnswFreeOffset(Relation index, Buffer buf, Page page, HnswElement element, Size ntupSize, Buffer *nbuf, Page *npage, OffsetNumber *freeOffno, OffsetNumber *freeNeighborOffno, BlockNumber *firstFreePage)
HnswFreeOffset(Relation index, Buffer buf, Page page, HnswElement element, Size ntupSize, Buffer *nbuf, Page *npage, OffsetNumber *freeOffno, OffsetNumber *freeNeighborOffno, BlockNumber *newInsertPage)
{
OffsetNumber offno;
OffsetNumber maxoffno = PageGetMaxOffsetNumber(page);
@@ -49,14 +49,15 @@ HnswFreeOffset(Relation index, Buffer buf, Page page, HnswElement element, Size
if (etup->deleted)
{
BlockNumber elementPage = BufferGetBlockNumber(buf);
BlockNumber neighborPage = ItemPointerGetBlockNumber(&etup->neighbortid);
OffsetNumber neighborOffno = ItemPointerGetOffsetNumber(&etup->neighbortid);
ItemId itemid;
if (!BlockNumberIsValid(*firstFreePage))
*firstFreePage = neighborPage;
if (!BlockNumberIsValid(*newInsertPage))
*newInsertPage = elementPage;
if (neighborPage == BufferGetBlockNumber(buf))
if (neighborPage == elementPage)
{
*nbuf = buf;
*npage = page;
@@ -110,7 +111,7 @@ HnswInsertAppendPage(Relation index, Buffer *nbuf, Page *npage, GenericXLogState
* Add to element and neighbor pages
*/
static void
WriteNewElementPages(Relation index, HnswElement e, int m, BlockNumber insertPage, BlockNumber *newInsertPage)
WriteNewElementPages(Relation index, HnswElement e, int m, BlockNumber insertPage, BlockNumber *updatedInsertPage)
{
Buffer buf;
Page page;
@@ -119,6 +120,7 @@ WriteNewElementPages(Relation index, HnswElement e, int m, BlockNumber insertPag
Size ntupSize;
Size combinedSize;
Size maxSize;
Size minCombinedSize;
HnswElementTuple etup;
BlockNumber originalInsertPage = insertPage;
int dimensions = e->vec->dim;
@@ -127,13 +129,14 @@ WriteNewElementPages(Relation index, HnswElement e, int m, BlockNumber insertPag
Page npage;
OffsetNumber freeOffno = InvalidOffsetNumber;
OffsetNumber freeNeighborOffno = InvalidOffsetNumber;
BlockNumber firstFreePage = InvalidBlockNumber;
BlockNumber newInsertPage = InvalidBlockNumber;
/* Calculate sizes */
etupSize = HNSW_ELEMENT_TUPLE_SIZE(dimensions);
ntupSize = HNSW_NEIGHBOR_TUPLE_SIZE(e->level, m);
combinedSize = etupSize + ntupSize + sizeof(ItemIdData);
maxSize = BLCKSZ - MAXALIGN(SizeOfPageHeaderData) - MAXALIGN(sizeof(HnswPageOpaqueData));
minCombinedSize = etupSize + HNSW_NEIGHBOR_TUPLE_SIZE(0, m) + sizeof(ItemIdData);
/* Prepare element tuple */
etup = palloc0(etupSize);
@@ -152,6 +155,10 @@ WriteNewElementPages(Relation index, HnswElement e, int m, BlockNumber insertPag
state = GenericXLogStart(index);
page = GenericXLogRegisterBuffer(state, buf, 0);
/* Check for size for element at level 0 */
if (!BlockNumberIsValid(newInsertPage) && PageGetFreeSpace(page) >= minCombinedSize)
newInsertPage = insertPage;
/* First, try the fastest path */
/* Space for both tuples on the current page */
/* This can split existing tuples in rare cases */
@@ -163,7 +170,7 @@ WriteNewElementPages(Relation index, HnswElement e, int m, BlockNumber insertPag
}
/* Next, try space from a deleted element */
if (HnswFreeOffset(index, buf, page, e, ntupSize, &nbuf, &npage, &freeOffno, &freeNeighborOffno, &firstFreePage))
if (HnswFreeOffset(index, buf, page, e, ntupSize, &nbuf, &npage, &freeOffno, &freeNeighborOffno, &newInsertPage))
{
if (nbuf != buf)
npage = GenericXLogRegisterBuffer(state, nbuf, 0);
@@ -223,7 +230,8 @@ WriteNewElementPages(Relation index, HnswElement e, int m, BlockNumber insertPag
e->blkno = BufferGetBlockNumber(buf);
e->neighborPage = BufferGetBlockNumber(nbuf);
insertPage = e->neighborPage;
if (!BlockNumberIsValid(newInsertPage))
newInsertPage = e->neighborPage;
if (OffsetNumberIsValid(freeOffno))
{
@@ -269,8 +277,8 @@ WriteNewElementPages(Relation index, HnswElement e, int m, BlockNumber insertPag
UnlockReleaseBuffer(nbuf);
/* Update the insert page */
if (insertPage != originalInsertPage && (!OffsetNumberIsValid(freeOffno) || firstFreePage == insertPage))
*newInsertPage = insertPage;
if (BlockNumberIsValid(newInsertPage) && newInsertPage != originalInsertPage)
*updatedInsertPage = newInsertPage;
}
/*

4
src/hnswvacuum.c
View File

@@ -416,7 +416,7 @@ MarkDeleted(HnswVacuumState * vacuumstate)
{
/* Set to first free page */
if (!BlockNumberIsValid(insertPage))
insertPage = ItemPointerGetBlockNumber(&etup->neighbortid);
insertPage = blkno;
continue;
}
@@ -479,7 +479,7 @@ MarkDeleted(HnswVacuumState * vacuumstate)
/* Set to first free page */
if (!BlockNumberIsValid(insertPage))
insertPage = neighborPage;
insertPage = blkno;
/* Prepare new xlog */
state = GenericXLogStart(index);