ALTER_SEQUENCE(7pg17)
β¨ ALTER SEQUENCE π
Okay bestie, so this page is about ALTER_SEQUENCE β it's the PostgreSQL 17.11 doc for changing the definition of a sequence generator πΈ. Think of it like giving your sequence a little glow-up: you can tweak its settings, swap its owner, rename it, move it to a new schema β all the main character moves β¨. Fr fr, let's get into it.
π SYNOPSIS π
ALTER SEQUENCE [ IF EXISTS ] name
[ AS data_type ]
[ INCREMENT [ BY ] increment ]
[ MINVALUE minvalue | NO MINVALUE ] [ MAXVALUE maxvalue | NO MAXVALUE ]
[ START [ WITH ] start ]
[ RESTART [ [ WITH ] restart ] ]
[ CACHE cache ] [ [ NO ] CYCLE ]
[ OWNED BY { table_name.column_name | NONE } ]
ALTER SEQUENCE [ IF EXISTS ] name SET { LOGGED | UNLOGGED }
ALTER SEQUENCE [ IF EXISTS ] name OWNER TO { new_owner | CURRENT_ROLE | CURRENT_USER | SESSION_USER }
ALTER SEQUENCE [ IF EXISTS ] name RENAME TO new_name
ALTER SEQUENCE [ IF EXISTS ] name SET SCHEMA new_schema
π DESCRIPTION β¨
So <pink>ALTER SEQUENCE</pink> changes the parameters of an existing sequence generator, periodt π
. Any parameters you don't specifically set in the command just keep their prior settings β no cap, they stay exactly where they were π«Ά.
Like, you literally must own the sequence to use ALTER SEQUENCE. And if you're changing a sequence's schema, you also need CREATE privilege on the new schema. To alter the owner, you have to be able to SET ROLE to the new owning role, and that role has to 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 π.)
π¦ PARAMETERS π
nameβ the name (optionally schema-qualified) of a sequence to be altered. iykyk.IF EXISTSβ do not throw an error if the sequence doesn't exist. A notice is issued in this case. So chill, bestie, it won't blow up π.data_typeβ the optional clauseAS data_typechanges the data type of the sequence. Valid types aresmallint,integer, andbigintβ¨.
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 don't fit into the new data type, an error will be generated π¨.
incrementβ the clauseINCREMENT BY incrementis optional. A positive value makes an ascending sequence, a negative one makes a descending sequence. If unspecified, the old increment value is maintained π.minvalue,NO MINVALUEβ the optional clauseMINVALUE minvaluedetermines the minimum value a sequence can generate. IfNO MINVALUEis specified, the defaults of1and 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 is maintained π.maxvalue,NO MAXVALUEβ the optional clauseMAXVALUE maxvaluedetermines the maximum value for the sequence. IfNO MAXVALUEis specified, the defaults of the maximum value of the data type and-1for ascending and descending sequences, respectively, will be used. If neither option is specified, the current maximum value is maintained πΈ.startβ the optional clauseSTART WITH startchanges the recorded start value of the sequence. This has no effect on the current sequence value; it simply sets the value that futureALTER SEQUENCE RESTARTcommands will use. It's giving "set it and forget it" energy π .restartβ the optional clauseRESTART [ WITH restart ]changes the current value of the sequence. This is similar to calling thesetvalfunction withis_called = false: the specified value will be returned by the next call ofnextval. WritingRESTARTwith no restart value is equivalent to supplying the start value that was recorded byCREATE SEQUENCEor last set byALTER SEQUENCE START WITHπ¦.
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. Lowkey important, bestie π₯.
cacheβ the clauseCACHE cacheenables sequence numbers to be preallocated and stored in memory for faster access. The minimum value is1(only one value can be generated at a time, i.e., no cache). If unspecified, the old cache value is maintained β‘.CYCLEβ the optionalCYCLEkey word can be used to enable the sequence to wrap around when themaxvalueorminvaluehas been reached by an ascending or descending sequence respectively. If the limit is reached, the next number generated will be theminvalueormaxvalue, respectively. It's giving circular energy π.NO CYCLEβ if the optionalNO CYCLEkey word is specified, any calls tonextvalafter the sequence has reached its maximum value will return an error. If neitherCYCLEnorNO CYCLEare specified, the old cycle behavior is maintained π.SET { LOGGED | UNLOGGED }β this form changes the sequence from unlogged to logged or vice-versa (seeCREATE SEQUENCE(CREATE_SEQUENCE(7))). It cannot be applied to a temporary sequence. No temporary glow-ups allowed π ββοΈ.OWNED BY table_name.column_name,OWNED BY NONEβ theOWNED BYoption 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. SpecifyingOWNED BY NONEremoves any existing association, making the sequence "free-standing" ποΈ.new_ownerβ the user name of the new owner of the sequence π.new_nameβ the new name for the sequence β¨.new_schemaβ the new schema for the sequence π.
π NOTES π§
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 is affected immediately, tho π
.
ALTER SEQUENCE does not affect the currval status for the sequence. (Before PostgreSQL 8.3, it sometimes did. Ancient history, bestie π.)
ALTER SEQUENCE blocks concurrent nextval, currval, lastval, and setval calls. It's a whole vibe check for concurrent access π¦.
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. Nostalgic, but valid π«Ά.
π EXAMPLES π
Restart a sequence called serial, at 105:
ALTER SEQUENCE serial RESTART WITH 105;
Slay, that's it. Short and iconic β¨.
π« COMPATIBILITY π
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. We're extra like that π
.
π₯ SEE ALSO πΈ
CREATE SEQUENCE(CREATE_SEQUENCE(7))DROP SEQUENCE(DROP_SEQUENCE(7))
PostgreSQL 17.11, dated 2026 β that's the tea, bestie πβ¨. Now go alter those sequences and live your main character era ππ.
π¦ where this page comes from
- opensuse-leap 16.0: postgresql17 17.11-160000.1.1 Β· PostgreSQL
- opensuse-leap 16.0: postgresql17 17.11-160000.1.1 Β· PostgreSQL
- opensuse-leap 16.0: postgresql17 17.11-160000.1.1 Β· PostgreSQL
- opensuse-leap 16.0: postgresql17 17.11-160000.1.1 Β· PostgreSQL
- π girlified by deepseek-ai/DeepSeek-V4.1-Flash-1017 on : a language model's rewrite of the original, under its terms