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Improved HNSW graph repair - #239

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This commit is contained in:
Andrew Kane
2023-08-26 14:06:03 -07:00
parent bb1e5ed98f
commit cfaa2ecd7f
1 changed files with 16 additions and 9 deletions
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25
src/hnswutils.c
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@@ -623,10 +623,6 @@ HnswSearchLayer(Datum q, List *ep, int ef, int lc, Relation index, FmgrInfo *pro
Assert(!e->element->deleted);
/* Skip self for vacuuming update */
if (skipElement != NULL && e->element->blkno == skipElement->blkno && e->element->offno == skipElement->offno)
continue;
/* Make robust to issues */
if (e->element->level < lc)
continue;
@@ -913,10 +909,10 @@ HnswUpdateConnection(HnswElement element, HnswCandidate * hc, int m, int lc, int
}
/*
* Remove elements being deleted
* Remove elements being deleted or skipped
*/
static List *
RemoveElementsBeingDeleted(List *w)
RemoveElements(List *w, HnswElement skipElement)
{
ListCell *lc2;
List *w2 = NIL;
@@ -925,6 +921,10 @@ RemoveElementsBeingDeleted(List *w)
{
HnswCandidate *hc = (HnswCandidate *) lfirst(lc2);
/* Skip self for vacuuming update */
if (skipElement != NULL && hc->element->blkno == skipElement->blkno && hc->element->offno == skipElement->offno)
continue;
if (list_length(hc->element->heaptids) != 0)
w2 = lappend(w2, hc);
}
@@ -963,20 +963,27 @@ HnswInsertElement(HnswElement element, HnswElement entryPoint, Relation index, F
if (level > entryLevel)
level = entryLevel;
/* Add one for existing element */
if (existing)
efConstruction++;
/* 2nd phase */
for (int lc = level; lc >= 0; lc--)
{
int lm = HnswGetLayerM(m, lc);
List *neighbors;
List *lw;
w = HnswSearchLayer(q, ep, efConstruction, lc, index, procinfo, collation, true, skipElement);
/* Elements being deleted can help with search */
/* Elements being deleted or skipped can help with search */
/* but should be removed before selecting neighbors */
if (index != NULL)
w = RemoveElementsBeingDeleted(w);
lw = RemoveElements(w, skipElement);
else
lw = w;
neighbors = SelectNeighbors(w, lm, lc, procinfo, collation, NULL);
neighbors = SelectNeighbors(lw, lm, lc, procinfo, collation, NULL);
AddConnections(element, neighbors, lm, lc);