52.53. pg_statistic_ext_data
pg_statistic_ext_data
The catalog pg_statistic_ext_data holds data for extended planner statistics defined in pg_statistic_ext.
Each row in this catalog corresponds to a statistics object created with CREATE STATISTICS.
Normally there is one entry, with stxdinherit = false, for each statistics object that has been analyzed.
If the table has inheritance children or partitions, a second entry with stxdinherit = true is also created.
This row represents the statistics object over the inheritance tree, i.e., statistics for the data you'd see with SELECT * FROM table*, whereas the stxdinherit = false row represents the results of SELECT * FROM ONLY table.
Like pg_statistic, pg_statistic_ext_data should not be readable by the public, since the contents might be considered sensitive. (Example: most common combinations of values in columns might be quite interesting.) pg_stats_ext is a publicly readable view on pg_statistic_ext_data (after joining with pg_statistic_ext) that only exposes information about tables the current user owns.
Column Type Description |
|---|
stxoid Extended statistics object containing the definition for this data |
stxdinherit If true, the stats include values from child tables, not just the values in the specified relation |
stxdndistinct N-distinct counts, serialized as pg_ndistinct type |
stxddependencies Functional dependency statistics, serialized as pg_dependencies type |
stxdmcv MCV (most-common values) list statistics, serialized as pg_mcv_list type |
stxdexpr Per-expression statistics, serialized as an array of pg_statistic type |
: pg_statistic_ext_data Columns