Sequence relation
A special single-row table containing metadata about a sequence
A sequence relation is a special single-row table containing metadata about a sequence.
The sequence relation's relkind in pg_class is S.
Notes
In PostgreSQL 9.6 and earlier, all information about the sequence was stored in the sequence relation. From PostgreSQL 10, all metadata not changed by nextval() is contained in the system catalogue table pg_sequence; see that entry for further details.
Examples
From PostgreSQL 10 and later:
postgres=# CREATE SEQUENCE foo;
CREATE SEQUENCE
postgres=# SELECT * from public.foo;
last_value | log_cnt | is_called
------------+---------+-----------
1 | 0 | f
(1 row)
In PostgreSQL 9.6 and earlier:
postgres=# CREATE SEQUENCE foo; CREATE SEQUENCE postgres=# SELECT * from public.foo; -[ RECORD 1 ]-+-------------------- sequence_name | foo last_value | 1 start_value | 1 increment_by | 1 max_value | 9223372036854775807 min_value | 1 cache_value | 1 log_cnt | 0 is_cycled | f is_called | f