1ALTER SEQUENCE(7) PostgreSQL 15.4 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
10 [ AS data_type ]
11 [ INCREMENT [ BY ] increment ]
12 [ MINVALUE minvalue | NO MINVALUE ] [ MAXVALUE maxvalue | NO MAXVALUE ]
13 [ START [ WITH ] start ]
14 [ RESTART [ [ WITH ] restart ] ]
15 [ CACHE cache ] [ [ NO ] CYCLE ]
16 [ OWNED BY { table_name.column_name | NONE } ]
17 ALTER SEQUENCE [ IF EXISTS ] name SET { LOGGED | UNLOGGED }
18 ALTER SEQUENCE [ IF EXISTS ] name OWNER TO { new_owner | CURRENT_ROLE | CURRENT_USER | SESSION_USER }
19 ALTER SEQUENCE [ IF EXISTS ] name RENAME TO new_name
20 ALTER SEQUENCE [ IF EXISTS ] name SET SCHEMA new_schema
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23 ALTER SEQUENCE changes the parameters of an existing sequence
24 generator. Any parameters not specifically set in the ALTER SEQUENCE
25 command retain their prior settings.
26 You must own the sequence to use ALTER SEQUENCE. To change a sequence's
28 schema, you must also have CREATE privilege on the new schema. To alter
29 the owner, you must also be a direct or indirect member of the new
30 owning role, and that role must have CREATE privilege on the sequence's
31 schema. (These restrictions enforce that altering the owner doesn't do
32 anything you couldn't do by dropping and recreating the sequence.
33 However, a superuser can alter ownership of any sequence anyway.)
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36 name
37 The name (optionally schema-qualified) of a sequence to be altered.
38 IF EXISTS
40 Do not throw an error if the sequence does not exist. A notice is
41 issued in this case.
42 data_type
44 The optional clause AS data_type changes the data type of the
45 sequence. Valid types are smallint, integer, and bigint.
46 Changing the data type automatically changes the minimum and
48 maximum values of the sequence if and only if the previous minimum
49 and maximum values were the minimum or maximum value of the old
50 data type (in other words, if the sequence had been created using
51 NO MINVALUE or NO MAXVALUE, implicitly or explicitly). Otherwise,
52 the minimum and maximum values are preserved, unless new values are
53 given as part of the same command. If the minimum and maximum
54 values do not fit into the new data type, an error will be
55 generated.
56 increment
58 The clause INCREMENT BY increment is optional. A positive value
59 will make an ascending sequence, a negative one a descending
60 sequence. If unspecified, the old increment value will be
61 maintained.
62 minvalue
64 NO MINVALUE
65 The optional clause MINVALUE minvalue determines the minimum value
66 a sequence can generate. If NO MINVALUE is specified, the defaults
67 of 1 and the minimum value of the data type for ascending and
68 descending sequences, respectively, will be used. If neither option
69 is specified, the current minimum value will be maintained.
70 maxvalue
72 NO MAXVALUE
73 The optional clause MAXVALUE maxvalue determines the maximum value
74 for the sequence. If NO MAXVALUE is specified, the defaults of the
75 maximum value of the data type and -1 for ascending and descending
76 sequences, respectively, will be used. If neither option is
77 specified, the current maximum value will be maintained.
78 start
80 The optional clause START WITH start changes the recorded start
81 value of the sequence. This has no effect on the current sequence
82 value; it simply sets the value that future ALTER SEQUENCE RESTART
83 commands will use.
84 restart
86 The optional clause RESTART [ WITH restart ] changes the current
87 value of the sequence. This is similar to calling the setval
88 function with is_called = false: the specified value will be
89 returned by the next call of nextval. Writing RESTART with no
90 restart value is equivalent to supplying the start value that was
91 recorded by CREATE SEQUENCE or last set by ALTER SEQUENCE START
92 WITH.
93 In contrast to a setval call, a RESTART operation on a sequence is
95 transactional and blocks concurrent transactions from obtaining
96 numbers from the same sequence. If that's not the desired mode of
97 operation, setval should be used.
98 cache
100 The clause CACHE cache enables sequence numbers to be preallocated
101 and stored in memory for faster access. The minimum value is 1
102 (only one value can be generated at a time, i.e., no cache). If
103 unspecified, the old cache value will be maintained.
104 CYCLE
106 The optional CYCLE key word can be used to enable the sequence to
107 wrap around when the maxvalue or minvalue has been reached by an
108 ascending or descending sequence respectively. If the limit is
109 reached, the next number generated will be the minvalue or
110 maxvalue, respectively.
111 NO CYCLE
113 If the optional NO CYCLE key word is specified, any calls to
114 nextval after the sequence has reached its maximum value will
115 return an error. If neither CYCLE or NO CYCLE are specified, the
116 old cycle behavior will be maintained.
117 SET { LOGGED | UNLOGGED }
119 This form changes the sequence from unlogged to logged or
120 vice-versa (see CREATE SEQUENCE (CREATE_SEQUENCE(7))). It cannot be
121 applied to a temporary sequence.
122 OWNED BY table_name.column_name
124 OWNED BY NONE
125 The OWNED BY option causes the sequence to be associated with a
126 specific table column, such that if that column (or its whole
127 table) is dropped, the sequence will be automatically dropped as
128 well. If specified, this association replaces any previously
129 specified association for the sequence. The specified table must
130 have the same owner and be in the same schema as the sequence.
131 Specifying OWNED BY NONE removes any existing association, making
132 the sequence “free-standing”.
133 new_owner
135 The user name of the new owner of the sequence.
136 new_name
138 The new name for the sequence.
139 new_schema
141 The new schema for the sequence.
142
144 ALTER SEQUENCE will not immediately affect nextval results in backends,
145 other than the current one, that have preallocated (cached) sequence
146 values. They will use up all cached values prior to noticing the
147 changed sequence generation parameters. The current backend will be
148 affected immediately.
149 ALTER SEQUENCE does not affect the currval status for the sequence.
151 (Before PostgreSQL 8.3, it sometimes did.)
152 ALTER SEQUENCE blocks concurrent nextval, currval, lastval, and setval
154 calls.
155 For historical reasons, ALTER TABLE can be used with sequences too; but
157 the only variants of ALTER TABLE that are allowed with sequences are
158 equivalent to the forms shown above.
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161 Restart a sequence called serial, at 105:
162 ALTER SEQUENCE serial RESTART WITH 105;
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166 ALTER SEQUENCE conforms to the SQL standard, except for the AS, START
167 WITH, OWNED BY, OWNER TO, RENAME TO, and SET SCHEMA clauses, which are
168 PostgreSQL extensions.
169
171 CREATE SEQUENCE (CREATE_SEQUENCE(7)), DROP SEQUENCE (DROP_SEQUENCE(7))
172PostgreSQL 15.4 2023 ALTER SEQUENCE(7)