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Removed checking neighbors for cached distance

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This commit is contained in:
Andrew Kane
2024-01-28 02:11:24 -08:00
parent e8e69278eb
commit 0cc883b944
1 changed files with 9 additions and 39 deletions
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48
src/hnswutils.c
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@@ -913,40 +913,10 @@ CompareCandidateDistancesOffset(const void *a, const void *b)
* Calculate the distance between elements * Calculate the distance between elements
*/ */
static float static float
HnswGetDistance(char *base, HnswElement a, HnswElement b, int lc, FmgrInfo *procinfo, Oid collation) HnswGetDistance(char *base, HnswElement a, HnswElement b, FmgrInfo *procinfo, Oid collation)
{ {
Datum aValue; Datum aValue = HnswGetValue(base, a);
Datum bValue; Datum bValue = HnswGetValue(base, b);
/* Look for cached distance */
if (!HnswPtrIsNull(base, a->neighbors))
{
HnswNeighborArray *neighbors = HnswGetNeighbors(base, a, lc);
for (int i = 0; i < neighbors->length; i++)
{
HnswElement element = HnswPtrAccess(base, neighbors->items[i].element);
if (element == b)
return neighbors->items[i].distance;
}
}
if (!HnswPtrIsNull(base, b->neighbors))
{
HnswNeighborArray *neighbors = HnswGetNeighbors(base, b, lc);
for (int i = 0; i < neighbors->length; i++)
{
HnswElement element = HnswPtrAccess(base, neighbors->items[i].element);
if (element == a)
return neighbors->items[i].distance;
}
}
aValue = HnswGetValue(base, a);
bValue = HnswGetValue(base, b);
return DatumGetFloat8(FunctionCall2Coll(procinfo, collation, aValue, bValue)); return DatumGetFloat8(FunctionCall2Coll(procinfo, collation, aValue, bValue));
} }
@@ -955,7 +925,7 @@ HnswGetDistance(char *base, HnswElement a, HnswElement b, int lc, FmgrInfo *proc
* Check if an element is closer to q than any element from R * Check if an element is closer to q than any element from R
*/ */
static bool static bool
CheckElementCloser(char *base, HnswCandidate * e, List *r, int lc, FmgrInfo *procinfo, Oid collation) CheckElementCloser(char *base, HnswCandidate * e, List *r, FmgrInfo *procinfo, Oid collation)
{ {
HnswElement eElement = HnswPtrAccess(base, e->element); HnswElement eElement = HnswPtrAccess(base, e->element);
ListCell *lc2; ListCell *lc2;
@@ -964,7 +934,7 @@ CheckElementCloser(char *base, HnswCandidate * e, List *r, int lc, FmgrInfo *pro
{ {
HnswCandidate *ri = lfirst(lc2); HnswCandidate *ri = lfirst(lc2);
HnswElement riElement = HnswPtrAccess(base, ri->element); HnswElement riElement = HnswPtrAccess(base, ri->element);
float distance = HnswGetDistance(base, eElement, riElement, lc, procinfo, collation); float distance = HnswGetDistance(base, eElement, riElement, procinfo, collation);
if (distance <= e->distance) if (distance <= e->distance)
return false; return false;
@@ -1010,7 +980,7 @@ SelectNeighbors(char *base, List *c, int lm, int lc, FmgrInfo *procinfo, Oid col
/* Use previous state of r and wd to skip work when possible */ /* Use previous state of r and wd to skip work when possible */
if (mustCalculate) if (mustCalculate)
e->closer = CheckElementCloser(base, e, r, lc, procinfo, collation); e->closer = CheckElementCloser(base, e, r, procinfo, collation);
else if (list_length(added) > 0) else if (list_length(added) > 0)
{ {
/* /*
@@ -1019,7 +989,7 @@ SelectNeighbors(char *base, List *c, int lm, int lc, FmgrInfo *procinfo, Oid col
*/ */
if (e->closer) if (e->closer)
{ {
e->closer = CheckElementCloser(base, e, added, lc, procinfo, collation); e->closer = CheckElementCloser(base, e, added, procinfo, collation);
if (!e->closer) if (!e->closer)
removedAny = true; removedAny = true;
@@ -1032,7 +1002,7 @@ SelectNeighbors(char *base, List *c, int lm, int lc, FmgrInfo *procinfo, Oid col
*/ */
if (removedAny) if (removedAny)
{ {
e->closer = CheckElementCloser(base, e, r, lc, procinfo, collation); e->closer = CheckElementCloser(base, e, r, procinfo, collation);
if (e->closer) if (e->closer)
added = lappend(added, e); added = lappend(added, e);
} }
@@ -1040,7 +1010,7 @@ SelectNeighbors(char *base, List *c, int lm, int lc, FmgrInfo *procinfo, Oid col
} }
else if (e == newCandidate) else if (e == newCandidate)
{ {
e->closer = CheckElementCloser(base, e, r, lc, procinfo, collation); e->closer = CheckElementCloser(base, e, r, procinfo, collation);
if (e->closer) if (e->closer)
added = lappend(added, e); added = lappend(added, e);
} }