Correct oversight in hashjoin cost estimation: nodeHash sizes its hash
Tom Lane <tgl@sss.pgh.pa.us>
Correct oversight in hashjoin cost estimation: nodeHash sizes its hash table for an average of NTUP_PER_BUCKET tuples/bucket, but cost_hashjoin was assuming a target load of one tuple/bucket. This was causing a noticeable underestimate of hashjoin costs.
Files
| Path | Change | +/− |
|---|---|---|
| src/backend/executor/nodeHash.c | modified | +1 −2 |
| src/backend/optimizer/path/costsize.c | modified | +11 −5 |
| src/include/executor/nodeHash.h | modified | +4 −1 |