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 52.51. 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.