Provided by: postgresql-client-8.0_8.0.7-2build1_i386
ALTER SEQUENCE - change the definition of a sequence generator
ALTER SEQUENCE name [ INCREMENT [ BY ] increment ]
[ MINVALUE minvalue | NO MINVALUE ] [ MAXVALUE maxvalue | NO MAXVALUE ]
[ RESTART [ WITH ] start ] [ CACHE cache ] [ [ NO ] CYCLE ]
ALTER SEQUENCE changes the parameters of an existing sequence
generator. Any parameter not specifically set in the ALTER SEQUENCE
command retains its prior setting.
name The name (optionally schema-qualified) of a sequence to be
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
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.
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
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.
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
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 behaviour will be maintained.
Restart a sequence called serial, at 105:
ALTER SEQUENCE serial RESTART WITH 105;
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
ALTER SEQUENCE conforms with SQL:2003.