53.52. pg_statistic

53.52. `pg_statistic_ext`
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53.52. `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 53.52. pg_statistic_ext Columns

+ Column Type + + + Description +
+ `oid` `oid` + + + Row identifier +
+ `stxrelid` `oid` + (references `pg_class`.`oid`) + + + Table containing the columns described by this object +
+ `stxname` `name` + + + Name of the statistics object +
+ `stxnamespace` `oid` + (references `pg_namespace`.`oid`) + + + The OID of the namespace that contains this statistics object +
+ `stxowner` `oid` + (references `pg_authid`.`oid`) + + + Owner of the statistics object +
+ `stxstattarget` `int4` + + + `stxstattarget` controls the level of detail + of statistics accumulated for this statistics object by + `ANALYZE`. + A zero value indicates that no statistics should be collected. + A negative value says to use the maximum of the statistics targets of + the referenced columns, if set, or the system default statistics target. + Positive values of `stxstattarget` + determine the target number of “most common values” + to collect. +
+ `stxkeys` `int2vector` + (references `pg_attribute`.`attnum`) + + + 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, + `m` for most common values (MCV) list statistics, and + `e` for expression statistics +
+ `stxexprs` `pg_node_tree` + + + Expression trees (in `nodeToString()` + representation) for statistics object attributes that are not simple + column references. This is a list with one element per expression. + Null if all statistics object attributes are simple references. +

+ Column Type +

+ Description +

+ oid oid +

+ Row identifier +

+ stxrelid oid + (references pg_class.oid) +

+ Table containing the columns described by this object +

+ stxname name +

+ Name of the statistics object +

+ stxnamespace oid + (references pg_namespace.oid) +

+ The OID of the namespace that contains this statistics object +

+ stxowner oid + (references pg_authid.oid) +

+ Owner of the statistics object +

+ stxstattarget int4 +

+ stxstattarget controls the level of detail + of statistics accumulated for this statistics object by + ANALYZE. + A zero value indicates that no statistics should be collected. + A negative value says to use the maximum of the statistics targets of + the referenced columns, if set, or the system default statistics target. + Positive values of stxstattarget + determine the target number of “most common values” + to collect. +

+ stxkeys int2vector + (references pg_attribute.attnum) +

+ 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, + m for most common values (MCV) list statistics, and + e for expression statistics +

+ stxexprs pg_node_tree +

+ Expression trees (in nodeToString() + representation) for statistics object attributes that are not simple + column references. This is a list with one element per expression. + Null if all statistics object attributes are simple references. +

+ 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. +

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53.51. `pg_statistic`	Home	53.53. `pg_statistic_ext_data`

53.52. pg_statistic_ext

53.52. `pg_statistic_ext`