diff options
Diffstat (limited to 'src/include/catalog/pg_statistic.h')
| -rw-r--r-- | src/include/catalog/pg_statistic.h | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/src/include/catalog/pg_statistic.h b/src/include/catalog/pg_statistic.h index 0e831ef2982..edccf254b1b 100644 --- a/src/include/catalog/pg_statistic.h +++ b/src/include/catalog/pg_statistic.h @@ -244,6 +244,8 @@ typedef FormData_pg_statistic *Form_pg_statistic; * type with identifiable elements (for instance, tsvector). staop contains * the equality operator appropriate to the element type. stavalues contains * the most common element values, and stanumbers their frequencies. Unlike + * MCV slots, frequencies are measured as the fraction of non-null rows the + * element value appears in, not the frequency of all rows. Also unlike * MCV slots, the values are sorted into order (to support binary search * for a particular value). Since this puts the minimum and maximum * frequencies at unpredictable spots in stanumbers, there are two extra |