diff options
| -rw-r--r-- | src/backend/commands/analyze.c | 16 |
1 files changed, 10 insertions, 6 deletions
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 44a4b3ff1e3..1283de03348 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -2133,13 +2133,15 @@ compute_distinct_stats(VacAttrStatsP stats, } else { - /* d here is the same as d in the Haas-Stokes formula */ - int d = nonnull_cnt - summultiple + nmultiple; + double ndistinct_table = stats->stadistinct; double avgcount, mincount; + /* Re-extract estimate of # distinct nonnull values in table */ + if (ndistinct_table < 0) + ndistinct_table = -ndistinct_table * totalrows; /* estimate # occurrences in sample of a typical nonnull value */ - avgcount = (double) nonnull_cnt / (double) d; + avgcount = (double) nonnull_cnt / ndistinct_table; /* set minimum threshold count to store a value */ mincount = avgcount * 1.25; if (mincount < 2) @@ -2493,14 +2495,16 @@ compute_scalar_stats(VacAttrStatsP stats, } else { - /* d here is the same as d in the Haas-Stokes formula */ - int d = ndistinct + toowide_cnt; + double ndistinct_table = stats->stadistinct; double avgcount, mincount, maxmincount; + /* Re-extract estimate of # distinct nonnull values in table */ + if (ndistinct_table < 0) + ndistinct_table = -ndistinct_table * totalrows; /* estimate # occurrences in sample of a typical nonnull value */ - avgcount = (double) values_cnt / (double) d; + avgcount = (double) nonnull_cnt / ndistinct_table; /* set minimum threshold count to store a value */ mincount = avgcount * 1.25; if (mincount < 2) |