53.53. 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
,
whereas the
table
*
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.
Table 53.53.
pg_statistic_ext_data
Columns
Column Type Description 

Extended statistics object containing the definition for this data 
If true, the stats include values from child tables, not just the values in the specified relation 
Ndistinct counts, serialized as

Functional dependency statistics, serialized
as

MCV (mostcommon values) list statistics, serialized as

Perexpression statistics, serialized as an array of
