pg_statistic_ext_data

The pg_statistic_ext_data system catalog table 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.

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 those tables and columns that are readable by the current user.

column	type	references	description
stxoid	oid	pg_statistic_ext.oid	The extended statistic object containing the definition for this data.
stxdndistinct	pg_ndistinct		N-distinct counts, serialized as pg_ndistinct type.
stxddependencies	pg_dependencies		Functional dependency statistics, serialized as pg_dependencies type.
stxdmcv	pg_mcv_list		MCV (most-common values) list statistics, serialized as pg_mcv_list type.
stxdexpr	ARRAY		Stores statistics for expressions defined in the extended statistics object. Each element of the array contains statistical data (similar to what pg_statistic holds for a column, such as null fraction, MCV, histogram.) for one of the expressions included in the CREATE STATISTICS definition, typically in an internal serialized format.