53.51. pg_statistic_ext
The catalog pg_statistic_ext
holds definitions of extended planner statistics. Each row in this catalog corresponds to a statistics object created with CREATE STATISTICS.
Table 53.51. pg_statistic_ext
Columns
Name | Type | References | Description |
---|---|---|---|
stxrelid | oid |
| Table containing the columns described by this object |
stxname | name | Name of the statistics object | |
stxnamespace | oid |
| The OID of the namespace that contains this statistics object |
stxowner | oid |
| Owner of the statistics object |
stxkeys | int2vector |
| An array of attribute numbers, indicating which table columns are covered by this statistics object; for example a value of 1 3 would mean that the first and the third table columns are covered |
stxkind | char[] | An array containing codes for the enabled statistics kinds; valid values are: d for n-distinct statistics, f for functional dependency statistics, and m for most common values (MCV) list statistics |
The pg_statistic_ext
entry is filled in completely during CREATE STATISTICS
, but the actual statistical values are not computed then. Subsequent ANALYZE
commands compute the desired values and populate an entry in the pg_statistic_ext_data
catalog.