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 51.50. pg_statistic_ext
Columns
Column Type Description 

Row identifier 
Table containing the columns described by this object 
Name of the statistics object 
The OID of the namespace that contains this statistics object 
Owner of the statistics object 

An array of attribute numbers, indicating which table columns are covered by this statistics object; for example a value of 
An array containing codes for the enabled statistic kinds; valid values are: 
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.