pg_statistic_ext
The catalog pg_statistic_ext
holds extended planner statistics. Each row in this catalog
corresponds to a statistics object
created with CREATE
STATISTICS.
Table 52.51. pg_statistic_ext
Columns
Name  Type  References  Description 

stxrelid 
oid 

Table containing the columns described by this object 
stxname 
name 
Name of the statistics object  
stxnamespace 
oid 

The OID of the namespace that contains this statistics object 
stxowner 
oid 

Owner of the statistics object 
stxkeys 
int2vector 

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 statistic
kinds; valid values are: d
for ndistinct statistics, f for functional dependency
statistics 

stxndistinct 
pg_ndistinct 
Ndistinct counts, serialized as pg_ndistinct type 

stxdependencies 
pg_dependencies 
Functional dependency statistics, serialized as
pg_dependencies
type 
The stxkind
field is filled
at creation of the statistics object, indicating which statistic
type(s) are desired. The fields after it are initially NULL and
are filled only when the corresponding statistic has been
computed by ANALYZE
.