52.51. pg_statistic_ext
The catalog
pg_statistic_ext
holds 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 statistic kinds;
valid values are:
d
for n-distinct statistics,
f
for functional dependency statistics
|
|
stxndistinct
|
pg_ndistinct
|
N-distinct counts, serialized as
pg_ndistinct
type
|
|
stxdependencies
|
pg_dependencies
|
Functional dependency statistics, serialized
as
pg_dependencies
type
|
The
stxkind
field is filled at creation of the
statistics object, indicating which statistic type(s) are desired.
The fields after it are initially NULL and are filled only when the
corresponding statistic has been computed by
ANALYZE
.