1ALTER SEQUENCE(7) PostgreSQL 9.2.24 Documentation ALTER SEQUENCE(7)
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6 ALTER_SEQUENCE - change the definition of a sequence generator
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9 ALTER SEQUENCE [ IF EXISTS ] name [ INCREMENT [ BY ] increment ]
10 [ MINVALUE minvalue | NO MINVALUE ] [ MAXVALUE maxvalue | NO MAXVALUE ]
11 [ START [ WITH ] start ]
12 [ RESTART [ [ WITH ] restart ] ]
13 [ CACHE cache ] [ [ NO ] CYCLE ]
14 [ OWNED BY { table_name.column_name | NONE } ]
15 ALTER SEQUENCE [ IF EXISTS ] name OWNER TO new_owner
16 ALTER SEQUENCE [ IF EXISTS ] name RENAME TO new_name
17 ALTER SEQUENCE [ IF EXISTS ] name SET SCHEMA new_schema
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20 ALTER SEQUENCE changes the parameters of an existing sequence
21 generator. Any parameters not specifically set in the ALTER SEQUENCE
22 command retain their prior settings.
23 You must own the sequence to use ALTER SEQUENCE. To change a sequence's
25 schema, you must also have CREATE privilege on the new schema. To alter
26 the owner, you must also be a direct or indirect member of the new
27 owning role, and that role must have CREATE privilege on the sequence's
28 schema. (These restrictions enforce that altering the owner doesn't do
29 anything you couldn't do by dropping and recreating the sequence.
30 However, a superuser can alter ownership of any sequence anyway.)
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33 name
34 The name (optionally schema-qualified) of a sequence to be altered.
35 IF EXISTS
37 Do not throw an error if the sequence does not exist. A notice is
38 issued in this case.
39 increment
41 The clause INCREMENT BY increment is optional. A positive value
42 will make an ascending sequence, a negative one a descending
43 sequence. If unspecified, the old increment value will be
44 maintained.
45 minvalue, NO MINVALUE
47 The optional clause MINVALUE minvalue determines the minimum value
48 a sequence can generate. If NO MINVALUE is specified, the defaults
49 of 1 and -263-1 for ascending and descending sequences,
50 respectively, will be used. If neither option is specified, the
51 current minimum value will be maintained.
52 maxvalue, NO MAXVALUE
54 The optional clause MAXVALUE maxvalue determines the maximum value
55 for the sequence. If NO MAXVALUE is specified, the defaults are
56 263-1 and -1 for ascending and descending sequences, respectively,
57 will be used. If neither option is specified, the current maximum
58 value will be maintained.
59 start
61 The optional clause START WITH start changes the recorded start
62 value of the sequence. This has no effect on the current sequence
63 value; it simply sets the value that future ALTER SEQUENCE RESTART
64 commands will use.
65 restart
67 The optional clause RESTART [ WITH restart ] changes the current
68 value of the sequence. This is equivalent to calling the setval
69 function with is_called = false: the specified value will be
70 returned by the next call of nextval. Writing RESTART with no
71 restart value is equivalent to supplying the start value that was
72 recorded by CREATE SEQUENCE or last set by ALTER SEQUENCE START
73 WITH.
74 cache
76 The clause CACHE cache enables sequence numbers to be preallocated
77 and stored in memory for faster access. The minimum value is 1
78 (only one value can be generated at a time, i.e., no cache). If
79 unspecified, the old cache value will be maintained.
80 CYCLE
82 The optional CYCLE key word can be used to enable the sequence to
83 wrap around when the maxvalue or minvalue has been reached by an
84 ascending or descending sequence respectively. If the limit is
85 reached, the next number generated will be the minvalue or
86 maxvalue, respectively.
87 NO CYCLE
89 If the optional NO CYCLE key word is specified, any calls to
90 nextval after the sequence has reached its maximum value will
91 return an error. If neither CYCLE or NO CYCLE are specified, the
92 old cycle behavior will be maintained.
93 OWNED BY table_name.column_name, OWNED BY NONE
95 The OWNED BY option causes the sequence to be associated with a
96 specific table column, such that if that column (or its whole
97 table) is dropped, the sequence will be automatically dropped as
98 well. If specified, this association replaces any previously
99 specified association for the sequence. The specified table must
100 have the same owner and be in the same schema as the sequence.
101 Specifying OWNED BY NONE removes any existing association, making
102 the sequence “free-standing”.
103 new_owner
105 The user name of the new owner of the sequence.
106 new_name
108 The new name for the sequence.
109 new_schema
111 The new schema for the sequence.
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114 To avoid blocking of concurrent transactions that obtain numbers from
115 the same sequence, ALTER SEQUENCE's effects on the sequence generation
116 parameters are never rolled back; those changes take effect immediately
117 and are not reversible. However, the OWNED BY, OWNER TO, RENAME TO, and
118 SET SCHEMA clauses cause ordinary catalog updates that can be rolled
119 back.
120 ALTER SEQUENCE will not immediately affect nextval results in backends,
122 other than the current one, that have preallocated (cached) sequence
123 values. They will use up all cached values prior to noticing the
124 changed sequence generation parameters. The current backend will be
125 affected immediately.
126 ALTER SEQUENCE does not affect the currval status for the sequence.
128 (Before PostgreSQL 8.3, it sometimes did.)
129 For historical reasons, ALTER TABLE can be used with sequences too; but
131 the only variants of ALTER TABLE that are allowed with sequences are
132 equivalent to the forms shown above.
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135 Restart a sequence called serial, at 105:
136 ALTER SEQUENCE serial RESTART WITH 105;
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140 ALTER SEQUENCE conforms to the SQL standard, except for the START WITH,
141 OWNED BY, OWNER TO, RENAME TO, and SET SCHEMA clauses, which are
142 PostgreSQL extensions.
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145 CREATE SEQUENCE (CREATE_SEQUENCE(7)), DROP SEQUENCE (DROP_SEQUENCE(7))
146PostgreSQL 9.2.24 2017-11-06 ALTER SEQUENCE(7)