1
0
mirror of https://github.com/postgres/postgres.git synced 2025-04-22 23:02:54 +03:00
Tom Lane f4230d2937 Change patternsel() so that instead of switching from a pure
pattern-examination heuristic method to purely histogram-driven selectivity at
histogram size 100, we compute both estimates and use a weighted average.
The weight put on the heuristic estimate decreases linearly with histogram
size, dropping to zero for 100 or more histogram entries.
Likewise in ltreeparentsel().  After a patch by Greg Stark, though I
reorganized the logic a bit to give the caller of histogram_selectivity()
more control.
2008-03-09 00:32:09 +00:00
..
2006-10-04 00:30:14 +00:00