Cause planner to make use of average-column-width statistic that is now
Tom Lane <tgl@sss.pgh.pa.us>
Cause planner to make use of average-column-width statistic that is now collected by ANALYZE. Also, add some modest amount of intelligence to guesses that are used for varlena columns in the absence of any ANALYZE statistics. The 'width' reported by EXPLAIN is finally something less than totally bogus for varlena columns ... and, in consequence, hashjoin estimating should be a little better ...
Files
| Path | Change | +/− |
|---|---|---|
| doc/src/sgml/perform.sgml | modified | +1 −8 |
| src/backend/optimizer/path/costsize.c | modified | +43 −32 |
| src/backend/utils/cache/lsyscache.c | modified | +77 −1 |
| src/include/utils/lsyscache.h | modified | +3 −1 |