51.51. pg_statistic_ext
The catalogpg_statistic_ext holds definitions of extended planner statistics. Each row in this catalog corresponds to astatistics object created withCREATE STATISTICS.
Table 51.51. 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 of1 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, andm for most common values (MCV) list statistics |
Thepg_statistic_ext entry is filled in completely duringCREATE STATISTICS, but the actual statistical values are not computed then. SubsequentANALYZE commands compute the desired values and populate an entry in thepg_statistic_ext_data catalog.