dump_statistic dumps the contents of the pg_statistic system catalog. It produces an INSERT statement per each tuple of the pg_statistic, excluding the ones that contain statistical data for tables in the information_schema and pg_catalog schemas.

The INSERT statement takes form of

WITH upsert as (
  UPDATE pg_catalog.pg_statistic SET column_name = expression [, ...]
  WHERE to_schema_qualified_relation(starelid) = t_relname
    AND to_attname(t_relname, staattnum) = t_attname
    AND to_atttype(t_relname, staattnum) = t_atttype
    AND stainherit = t_stainherit
  RETURNING *)
ins as (
  SELECT expression [, ...]
  WHERE NOT EXISTS (SELECT * FROM upsert)
    AND to_attnum(t_relname, t_attname) IS NOT NULL
    AND to_atttype(t_relname, t_attname) = t_atttype)
INSERT INTO pg_catalog.pg_statistic SELECT * FROM ins;

where expression can be one of:

array_in(array_text, type_name::regtype::oid, -1)
value::type_name

Produced statements could be saved to a file, e.g.

$ psql test -A
test=# \t
test=# \o dump_stat.sql
test=# select dump_statistic();

dump_statistic dumps the contents of the pg_statistic system catalog. It produces an INSERT statement per each tuple of the pg_statistic that relates to some table in the schema_name schema.

dump_statistic dumps the contents of the pg_statistic system catalog. It produces an INSERT statement per each tuple of the pg_statistic that relates to the specified schema_name.table_name table.

dump_statistic dumps the contents of the pg_statistic system catalog. It produces an INSERT statement per each tuple of the pg_statistic that contains statistical data for the relation referenced by relid.

Fetches the schema-qualified operator name by operator id opid. For example:

test=# SELECT to_schema_qualified_operator('+(int,int)'::regoperator);
          to_schema_qualified_operator          
------------------------------------------------
 pg_catalog.+(pg_catalog.int4, pg_catalog.int4)
(1 row)

Fetches the schema-qualified type name by type id typid.

Fetches the schema-qualified relation name by relation id relid.

Returns the element type of the given array as oid. For example:

test=# SELECT anyarray_elemtype(array_in('{1,2,3}', 'int'::regtype, -1));
 anyarray_elemtype 
-------------------
                23
(1 row)

Given a relation name relation and a column number colnum, returns the column name as text.

Given a relation name relation and a column name col, returns the column number as int2.

Given a relation name relation and a column name col, returns the schema-qualified column type as text.

Given a relation name relation and a column number colnum, returns the schema-qualified column type as text.

to_namespace duplicates the behavior of the cast to the regnamespace type, which is not present in the PostgreSQL 9.4 release (and prior releases). This function returns the oid of the given schema.

get_namespace returns the schema of the given relation as oid.