/usr/man2/cat.l/alter_sequence.l.Z

NAME

       ALTER SEQUENCE - change the definition of a sequence generator

SYNOPSIS

       ALTER SEQUENCE name [ INCREMENT [ BY ] increment ]
           [ MINVALUE minvalue | NO MINVALUE ] [ MAXVALUE maxvalue | NO MAXVALUE ]
           [ RESTART [ WITH ] start ] [ CACHE cache ] [ [ NO ] CYCLE ]
       ALTER SEQUENCE name SET SCHEMA new_schema

DESCRIPTION

       ALTER  SEQUENCE  changes the parameters of an existing sequence genera-
       tor. 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.

PARAMETERS

       name   The  name  (optionally  schema-qualified)  of  a  sequence to be
              altered.

       increment
              The clause INCREMENT BY increment is optional. A positive  value
              will  make  an  ascending  sequence, a negative one a descending
              sequence. If unspecified, the old increment value will be  main-
              tained.

       minvalue

       NO MINVALUE
              The  optional  clause  MINVALUE  minvalue determines the minimum
              value a sequence can generate. If NO MINVALUE is specified,  the
              defaults of 1 and -263-1 for ascending and descending sequences,
              respectively, will be used. If neither option is specified,  the
              current minimum value will be maintained.

       maxvalue

       NO MAXVALUE
              The  optional  clause  MAXVALUE  maxvalue determines the maximum
              value for  the  sequence.  If  NO  MAXVALUE  is  specified,  the
              defaults   are   263-1  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 RESTART WITH start changes the current value
              of the sequence.

       cache  The clause CACHE cache enables sequence numbers to  be  preallo-
              cated  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.

       CYCLE  The optional CYCLE key word may 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.

       new_schema
              The new schema for the sequence.

EXAMPLES

       Restart a sequence called serial, at 105:

       ALTER SEQUENCE serial RESTART WITH 105;

NOTES

       To  avoid  blocking of concurrent transactions that obtain numbers from
       the same sequence, ALTER SEQUENCE is never  rolled  back;  the  changes
       take effect immediately and are not reversible.

       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 parameters. The current backend will be affected imme-
       diately.

       Some  variants  of  ALTER TABLE can be used with sequences as well; for
       example, to rename a sequence use ALTER TABLE RENAME.

COMPATIBILITY

       ALTER SEQUENCE conforms to the SQL standard, except for the SET  SCHEMA
       variant, which is a PostgreSQL extension.

SQL - Language Statements         2005-11-05                  ALTER SEQUENCE()