ALTER SEQUENCE — change the definition of a sequence generator
ALTER SEQUENCE [ IF EXISTS ]name[ ASdata_type] [ INCREMENT [ BY ]increment] [ MINVALUEminvalue| NO MINVALUE ] [ MAXVALUEmaxvalue| NO MAXVALUE ] [ START [ WITH ]start] [ RESTART [ [ WITH ]restart] ] [ CACHEcache] [ [ NO ] CYCLE ] [ OWNED BY {table_name.column_name| NONE } ] ALTER SEQUENCE [ IF EXISTS ]nameSET { LOGGED | UNLOGGED } ALTER SEQUENCE [ IF EXISTS ]nameOWNER TO {new_owner| CURRENT_ROLE | CURRENT_USER | SESSION_USER } ALTER SEQUENCE [ IF EXISTS ]nameRENAME TOnew_nameALTER SEQUENCE [ IF EXISTS ]nameSET SCHEMAnew_schema
   ALTER SEQUENCE changes the parameters of an existing
   sequence generator.  Any parameters not specifically set in the
   ALTER SEQUENCE command retain their prior settings.
  
   You must own the sequence to use ALTER SEQUENCE.
   To change a sequence's schema, you must also have CREATE
   privilege on the new schema.
   To alter the owner, you must be able to SET ROLE to the
   new owning role, and that role must have CREATE
   privilege on the sequence's schema.
   (These restrictions enforce that altering the owner
   doesn't do anything you couldn't do by dropping and recreating the sequence.
   However, a superuser can alter ownership of any sequence anyway.)
  
nameThe name (optionally schema-qualified) of a sequence to be altered.
IF EXISTSDo not throw an error if the sequence does not exist. A notice is issued in this case.
data_type
        The optional
        clause AS 
        changes the data type of the sequence.  Valid types are
        data_typesmallint, integer,
        and bigint.
       
        Changing the data type automatically changes the minimum and maximum
        values of the sequence if and only if the previous minimum and maximum
        values were the minimum or maximum value of the old data type (in
        other words, if the sequence had been created using NO
        MINVALUE or NO MAXVALUE, implicitly or
        explicitly).  Otherwise, the minimum and maximum values are preserved,
        unless new values are given as part of the same command.  If the
        minimum and maximum values do not fit into the new data type, an error
        will be generated.
       
increment
        The clause INCREMENT BY  is
        optional. A positive value will make an ascending sequence, a
        negative one a descending sequence.  If unspecified, the old
        increment value will be maintained.
       increment
minvalueNO MINVALUE
        The optional clause MINVALUE  determines
        the minimum value a sequence can generate. If minvalueNO
        MINVALUE is specified, the defaults of 1 and
        the minimum value of the data type for ascending and descending sequences,
        respectively, will be used.  If neither option is specified,
        the current minimum value will be maintained.
       
maxvalueNO MAXVALUE
        The optional clause MAXVALUE  determines
        the maximum value for the sequence. If maxvalueNO
        MAXVALUE is specified, the defaults of
        the maximum value of the data type and -1 for ascending and descending
        sequences, respectively, will be used.  If neither option is
        specified, the current maximum value will be maintained.
       
start
        The optional clause START WITH  changes the
        recorded start value of the sequence.  This has no effect on the
        current sequence value; it simply sets the value
        that future startALTER SEQUENCE RESTART commands will use.
       
restart
        The optional clause RESTART [ WITH  changes the
        current value of the sequence.  This is similar to calling the
        restart ]setval function with is_called =
        false: the specified value will be returned by the
        next call of nextval.
        Writing RESTART with no restart value is equivalent to supplying
        the start value that was recorded by CREATE SEQUENCE
        or last set by ALTER SEQUENCE START WITH.
       
        In contrast to a setval call,
        a RESTART operation on a sequence is transactional
        and blocks concurrent transactions from obtaining numbers from the
        same sequence. If that's not the desired mode of
        operation, setval should be used.
       
cache
        The clause CACHE  enables
        sequence numbers to be preallocated and stored in memory for
        faster access. The minimum value is 1 (only one value can be
        generated at a time, i.e., no cache).  If unspecified, the old
        cache value will be maintained.
       cache
CYCLE
        The optional CYCLE key word can be used to enable
        the sequence to wrap around when the
        maxvalue or
        minvalue has been
        reached by
        an ascending or descending sequence respectively. If the limit is
        reached, the next number generated will be the
        minvalue or
        maxvalue,
        respectively.
       
NO CYCLE
        If the optional NO CYCLE key word is
        specified, any calls to nextval after the
        sequence has reached its maximum value will return an error.
        If neither CYCLE or NO
        CYCLE are specified, the old cycle behavior will be
        maintained.
       
SET { LOGGED | UNLOGGED }This form changes the sequence from unlogged to logged or vice-versa (see CREATE SEQUENCE). It cannot be applied to a temporary sequence.
OWNED BY table_name.column_nameOWNED BY NONE
      The OWNED BY option causes the sequence to be
      associated with a specific table column, such that if that column
      (or its whole table) is dropped, the sequence will be automatically
      dropped as well.  If specified, this association replaces any
      previously specified association for the sequence.  The specified
      table must have the same owner and be in the same schema as the
      sequence.
      Specifying OWNED BY NONE removes any existing
      association, making the sequence “free-standing”.
     
new_ownerThe user name of the new owner of the sequence.
new_nameThe new name for the sequence.
new_schemaThe new schema for the sequence.
   ALTER SEQUENCE will not immediately affect
   nextval results in backends,
   other than the current one, that have preallocated (cached) sequence
   values. They will use up all cached values prior to noticing the changed
   sequence generation parameters.  The current backend will be affected
   immediately.
  
   ALTER SEQUENCE does not affect the currval
   status for the sequence.  (Before PostgreSQL
   8.3, it sometimes did.)
  
   ALTER SEQUENCE blocks
   concurrent nextval, currval,
   lastval, and setval calls.
  
   For historical reasons, ALTER TABLE can be used with
   sequences too; but the only variants of ALTER TABLE
   that are allowed with sequences are equivalent to the forms shown above.
  
   Restart a sequence called serial, at 105:
ALTER SEQUENCE serial RESTART WITH 105;
   ALTER SEQUENCE conforms to the SQL
   standard, except for the AS, START WITH,
   OWNED BY, OWNER TO, RENAME TO, and
   SET SCHEMA clauses, which are
   PostgreSQL extensions.