diff options
| -rw-r--r-- | src/backend/commands/analyze.c | 28 |
1 files changed, 25 insertions, 3 deletions
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 45f8c234c15..ff20cf96967 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -8,7 +8,7 @@ * * * IDENTIFICATION - * $PostgreSQL: pgsql/src/backend/commands/analyze.c,v 1.81 2005/01/27 23:23:53 neilc Exp $ + * $PostgreSQL: pgsql/src/backend/commands/analyze.c,v 1.82 2005/02/11 00:41:12 tgl Exp $ * *------------------------------------------------------------------------- */ @@ -1548,7 +1548,7 @@ compute_minimal_stats(VacAttrStatsP stats, } } - /* We can only compute valid stats if we found some non-null values. */ + /* We can only compute real stats if we found some non-null values. */ if (nonnull_cnt > 0) { int nmultiple, @@ -1705,6 +1705,17 @@ compute_minimal_stats(VacAttrStatsP stats, stats->numvalues[0] = num_mcv; } } + else if (null_cnt > 0) + { + /* We found only nulls; assume the column is entirely null */ + stats->stats_valid = true; + stats->stanullfrac = 1.0; + if (is_varwidth) + stats->stawidth = 0; /* "unknown" */ + else + stats->stawidth = stats->attrtype->typlen; + stats->stadistinct = 0.0; /* "unknown" */ + } /* We don't need to bother cleaning up any of our temporary palloc's */ } @@ -1812,7 +1823,7 @@ compute_scalar_stats(VacAttrStatsP stats, values_cnt++; } - /* We can only compute valid stats if we found some sortable values. */ + /* We can only compute real stats if we found some sortable values. */ if (values_cnt > 0) { int ndistinct, /* # distinct values in sample */ @@ -2162,6 +2173,17 @@ compute_scalar_stats(VacAttrStatsP stats, slot_idx++; } } + else if (nonnull_cnt == 0 && null_cnt > 0) + { + /* We found only nulls; assume the column is entirely null */ + stats->stats_valid = true; + stats->stanullfrac = 1.0; + if (is_varwidth) + stats->stawidth = 0; /* "unknown" */ + else + stats->stawidth = stats->attrtype->typlen; + stats->stadistinct = 0.0; /* "unknown" */ + } /* We don't need to bother cleaning up any of our temporary palloc's */ } |