title: ALTER_OPERATOR_FAMILY(7)

text:
# ALTER_OPERATOR_FAMILY(7)

## NAME
ALTER_OPERATOR_FAMILY - change the definition of an operator family

## SYNOPSIS

```
ALTER OPERATOR FAMILY name USING index_method ADD

  {  OPERATOR strategy_number operator_name ( op_type, op_type )

              [ FOR SEARCH | FOR ORDER BY sort_family_name ]

   | FUNCTION support_number [ ( op_type [ , op_type ] ) ]

              function_name [ ( argument_type [, ...] ) ]

  } [, ... ]
ALTER OPERATOR FAMILY name USING index_method DROP

  {  OPERATOR strategy_number ( op_type [ , op_type ] )

   | FUNCTION support_number ( op_type [ , op_type ] )

  } [, ... ]
ALTER OPERATOR FAMILY name USING index_method

    RENAME TO new_name
ALTER OPERATOR FAMILY name USING index_method

    OWNER TO { new_owner | CURRENT_ROLE | CURRENT_USER | SESSION_USER }
ALTER OPERATOR FAMILY name USING index_method

    SET SCHEMA new_schema
```

## DESCRIPTION
ALTER OPERATOR FAMILY changes the definition of an operator family. You can add operators and support functions to the family, remove them from the family, or change the family's name or owner.

When operators and support functions are added to a family with ALTER OPERATOR FAMILY, they are not part of any specific operator class within the family, but are just “loose” within the family. This indicates that these operators and functions are compatible with the family's semantics, but are not required for correct functioning of any specific index. (Operators and functions that are so required should be declared as part of an operator class, instead; see CREATE OPERATOR CLASS (CREATE_OPERATOR_CLASS(7)).) PostgreSQL will allow loose members of a family to be dropped from the family at any time, but members of an operator class cannot be dropped without dropping the whole class and any indexes that depend on it. Typically, single-data-type operators and functions are part of operator classes because they are needed to support an index on that specific data type, while cross-data-type operators and functions are made loose members of the family.

You must be a superuser to use ALTER OPERATOR FAMILY. (This restriction is made because an erroneous operator family definition could confuse or even crash the server.)

ALTER OPERATOR FAMILY does not presently check whether the operator family definition includes all the operators and functions required by the index method, nor whether the operators and functions form a self-consistent set. It is the user's responsibility to define a valid operator family.

Refer to Section 38.16 for further information.

## PARAMETERS
name

The name (optionally schema-qualified) of an existing operator family.

index_method

The name of the index method this operator family is for.

strategy_number

The index method's strategy number for an operator associated with the operator family.

operator_name

The name (optionally schema-qualified) of an operator associated with the operator family.

op_type

In an OPERATOR clause, the operand data type(s) of the operator, or NONE to signify a prefix operator. Unlike the comparable syntax in CREATE OPERATOR CLASS, the operand data types must always be specified. In an ADD FUNCTION clause, the operand data type(s) the function is intended to support, if different from the input data type(s) of the function. For B-tree comparison functions and hash functions it is not necessary to specify op_type since the function's input data type(s) are always the correct ones to use. For B-tree sort support functions, B-Tree equal image functions, and all functions in GiST, SP-GiST and GIN operator classes, it is necessary to specify the operand data type(s) the function is to be used with.

In a DROP FUNCTION clause, the operand data type(s) the function is intended to support must be specified.

sort_family_name

The name (optionally schema-qualified) of an existing btree operator family that describes the sort ordering associated with an ordering operator. If neither FOR SEARCH nor FOR ORDER BY is specified, FOR SEARCH is the default.

support_number

The index method's support function number for a function associated with the operator family.

function_name

The name (optionally schema-qualified) of a function that is an index method support function for the operator family. If no argument list is specified, the name must be unique in its schema.

argument_type

The parameter data type(s) of the function.

new_name

The new name of the operator family.

new_owner

The new owner of the operator family.

new_schema

The new schema for the operator family.

The OPERATOR and FUNCTION clauses can appear in any order.

## NOTES
Notice that the DROP syntax only specifies the “slot” in the operator family, by strategy or support number and input data type(s). The name of the operator or function occupying the slot is not mentioned. Also, for DROP FUNCTION the type(s) to specify are the input data type(s) the function is intended to support; for GiST, SP-GiST and GIN indexes this might have nothing to do with the actual input argument types of the function.

Because the index machinery does not check access permissions on functions before using them, including a function or operator in an operator family is tantamount to granting public execute permission on it. This is usually not an issue for the sorts of functions that are useful in an operator family.

The operators should not be defined by SQL functions. An SQL function is likely to be inlined into the calling query, which will prevent the optimizer from recognizing that the query matches an index.

Before PostgreSQL 8.4, the OPERATOR clause could include a RECHECK option. This is no longer supported because whether an index operator is “lossy” is now determined on-the-fly at run time. This allows efficient handling of cases where an operator might or might not be lossy.

## EXAMPLES
The following example command adds cross-data-type operators and support functions to an operator family that already contains B-tree operator classes for data types int4 and int2.

```
ALTER OPERATOR FAMILY integer_ops USING btree ADD

  -- int4 vs int2

  OPERATOR 1 < (int4, int2) ,

  OPERATOR 2 <= (int4, int2) ,

  OPERATOR 3 = (int4, int2) ,

  OPERATOR 4 >= (int4, int2) ,

  OPERATOR 5 > (int4, int2) ,

  FUNCTION 1 btint42cmp(int4, int2) ,

  -- int2 vs int4

  OPERATOR 1 < (int2, int4) ,

  OPERATOR 2 <= (int2, int4) ,

  OPERATOR 3 = (int2, int4) ,

  OPERATOR 4 >= (int2, int4) ,

  OPERATOR 5 > (int2, int4) ,

  FUNCTION 1 btint24cmp(int2, int4) ;
```

To remove these entries again:

```
ALTER OPERATOR FAMILY integer_ops USING btree DROP

  -- int4 vs int2

  OPERATOR 1 (int4, int2) ,

  OPERATOR 2 (int4, int2) ,

  OPERATOR 3 (int4, int2) ,

  OPERATOR 4 (int4, int2) ,

  OPERATOR 5 (int4, int2) ,

  FUNCTION 1 (int4, int2) ,

  -- int2 vs int4

  OPERATOR 1 (int2, int4) ,

  OPERATOR 2 (int2, int4) ,

  OPERATOR 3 (int2, int4) ,

  OPERATOR 4 (int2, int4) ,

  OPERATOR 5 (int2, int4) ,

  FUNCTION 1 (int2, int4) ;
```

## COMPATIBILITY
There is no ALTER OPERATOR FAMILY statement in the SQL standard.

## SEE ALSO
CREATE OPERATOR FAMILY (CREATE_OPERATOR_FAMILY(7)), DROP OPERATOR FAMILY (DROP_OPERATOR_FAMILY(7)), CREATE OPERATOR CLASS (CREATE_OPERATOR_CLASS(7)), ALTER OPERATOR CLASS (ALTER_OPERATOR_CLASS(7)), DROP OPERATOR CLASS (DROP_OPERATOR_CLASS(7))


title: ALTER_POLICY(7)

summary: change the definition of a row\-level security policy

text:
# ALTER_POLICY(7)

## NAME
ALTER_POLICY - change the definition of a row-level security policy

## SYNOPSIS

```
ALTER POLICY name ON table_name RENAME TO new_name
ALTER POLICY name ON table_name

    [ TO { role_name | PUBLIC | CURRENT_ROLE | CURRENT_USER | SESSION_USER } [, ...] ]

    [ USING ( using_expression ) ]

    [ WITH CHECK ( check_expression ) ]
```

## DESCRIPTION
ALTER POLICY changes the definition of an existing row-level security policy. Note that ALTER POLICY only allows the set of roles to which the policy applies and the USING and WITH CHECK expressions to be modified. To change other properties of a policy, such as the command to which it applies or whether it is permissive or restrictive, the policy must be dropped and recreated.

To use ALTER POLICY, you must own the table that the policy applies to.

In the second form of ALTER POLICY, the role list, using_expression, and check_expression are replaced independently if specified. When one of those clauses is omitted, the corresponding part of the policy is unchanged.

## PARAMETERS
name

The name of an existing policy to alter.

table_name

The name (optionally schema-qualified) of the table that the policy is on.

new_name

The new name for the policy.

role_name

The role(s) to which the policy applies. Multiple roles can be specified at one time. To apply the policy to all roles, use PUBLIC.

using_expression

The USING expression for the policy. See CREATE POLICY (CREATE_POLICY(7)) for details.

check_expression

The WITH CHECK expression for the policy. See CREATE POLICY (CREATE_POLICY(7)) for details.

## COMPATIBILITY
ALTER POLICY is a PostgreSQL extension.

## SEE ALSO
CREATE POLICY (CREATE_POLICY(7)), DROP POLICY (DROP_POLICY(7))


title: ALTER_PROCEDURE(7)

summary: change the definition of a procedure

text:
# ALTER_PROCEDURE(7)

## NAME
ALTER_PROCEDURE - change the definition of a procedure

## SYNOPSIS

```
ALTER PROCEDURE name [ ( [ [ argmode ] [ argname ] argtype [, ...] ] ) ]

    action [ ... ] [ RESTRICT ]
ALTER PROCEDURE name [ ( [ [ argmode ] [ argname ] argtype [, ...] ] ) ]

    RENAME TO new_name
ALTER PROCEDURE name [ ( [ [ argmode ] [ argname ] argtype [, ...] ] ) ]

    OWNER TO { new_owner | CURRENT_ROLE | CURRENT_USER | SESSION_USER }
ALTER PROCEDURE name [ ( [ [ argmode ] [ argname ] argtype [, ...] ] ) ]

    SET SCHEMA new_schema
ALTER PROCEDURE name [ ( [ [ argmode ] [ argname ] argtype [, ...] ] ) ]

    [ NO ] DEPENDS ON EXTENSION extension_name
where action is one of:

    [ EXTERNAL ] SECURITY INVOKER | [ EXTERNAL ] SECURITY DEFINER

    SET configuration_parameter { TO | = } { value | DEFAULT }

    SET configuration_parameter FROM CURRENT

    RESET configuration_parameter

    RESET ALL
```

## DESCRIPTION
ALTER PROCEDURE changes the definition of a procedure.

You must own the procedure to use ALTER PROCEDURE. To change a procedure's schema, you must also have CREATE privilege on the new schema. To alter the owner, you must also be a direct or indirect member of the new owning role, and that role must have CREATE privilege on the procedure's schema. (These restrictions enforce that altering the owner doesn't do anything you couldn't do by dropping and recreating the procedure. However, a superuser can alter ownership of any procedure anyway.)

## PARAMETERS
name

The name (optionally schema-qualified) of an existing procedure. If no argument list is specified, the name must be unique in its schema.

argmode

The mode of an argument: IN, OUT, INOUT, or VARIADIC. If omitted, the default is IN.

argname

The name of an argument. Note that ALTER PROCEDURE does not actually pay any attention to argument names, since only the argument data types are used to determine the procedure's identity.

argtype

The data type(s) of the procedure's arguments (optionally schema-qualified), if any. See DROP PROCEDURE (DROP_PROCEDURE(7)) for the details of how the procedure is looked up using the argument data type(s).

new_name

The new name of the procedure.

new_owner

The new owner of the procedure. Note that if the procedure is marked SECURITY DEFINER, it will subsequently execute as the new owner.

new_schema

The new schema for the procedure.

extension_name

This form marks the procedure as dependent on the extension, or no longer dependent on the extension if NO is specified. A procedure that's marked as dependent on an extension is dropped when the extension is dropped, even if cascade is not specified. A procedure can depend upon multiple extensions, and will be dropped when any one of those extensions is dropped.

[ EXTERNAL ] SECURITY INVOKER

[ EXTERNAL ] SECURITY DEFINER

Change whether the procedure is a security definer or not. The key word EXTERNAL is ignored for SQL conformance. See CREATE PROCEDURE (CREATE_PROCEDURE(7)) for more information about this capability.

configuration_parameter

value

Add or change the assignment to be made to a configuration parameter when the procedure is called. If value is DEFAULT or, equivalently, RESET is used, the procedure-local setting is removed, so that the procedure executes with the value present in its environment. Use RESET ALL to clear all procedure-local settings. SET FROM CURRENT saves the value of the parameter that is current when ALTER PROCEDURE is executed as the value to be applied when the procedure is entered. See SET(7) and Chapter 20 for more information about allowed parameter names and values.

RESTRICT

Ignored for conformance with the SQL standard.

## EXAMPLES
To rename the procedure insert_data with two arguments of type integer to insert_record:

```
ALTER PROCEDURE insert_data(integer, integer) RENAME TO insert_record;
```

To change the owner of the procedure insert_data with two arguments of type integer to joe:

```
ALTER PROCEDURE insert_data(integer, integer) OWNER TO joe;
```

To change the schema of the procedure insert_data with two arguments of type integer to accounting:

```
ALTER PROCEDURE insert_data(integer, integer) SET SCHEMA accounting;
```

To mark the procedure insert_data(integer, integer) as being dependent on the extension myext:

```
ALTER PROCEDURE insert_data(integer, integer) DEPENDS ON EXTENSION myext;
```

To adjust the search path that is automatically set for a procedure:

```
ALTER PROCEDURE check_password(text) SET search_path = admin, pg_temp;
```

To disable automatic setting of search_path for a procedure:

```
ALTER PROCEDURE check_password(text) RESET search_path;
```

The procedure will now execute with whatever search path is used by its caller.

## COMPATIBILITY
This statement is partially compatible with the ALTER PROCEDURE statement in the SQL standard. The standard allows more properties of a procedure to be modified, but does not provide the ability to rename a procedure, make a procedure a security definer, attach configuration parameter values to a procedure, or change the owner, schema, or volatility of a procedure. The standard also requires the RESTRICT key word, which is optional in PostgreSQL.

## SEE ALSO
CREATE PROCEDURE (CREATE_PROCEDURE(7)), DROP PROCEDURE (DROP_PROCEDURE(7)), ALTER FUNCTION (ALTER_FUNCTION(7)), ALTER ROUTINE (ALTER_ROUTINE(7))


title: ALTER_PUBLICATION(7)

summary: change the definition of a publication

text:
# ALTER_PUBLICATION(7)

## NAME
ALTER_PUBLICATION - change the definition of a publication

## SYNOPSIS

```
ALTER PUBLICATION name ADD TABLE [ ONLY ] table_name [ * ] [, ...]
ALTER PUBLICATION name SET TABLE [ ONLY ] table_name [ * ] [, ...]
ALTER PUBLICATION name DROP TABLE [ ONLY ] table_name [ * ] [, ...]
ALTER PUBLICATION name SET ( publication_parameter [= value] [, ... ] )
ALTER PUBLICATION name OWNER TO { new_owner | CURRENT_ROLE | CURRENT_USER | SESSION_USER }
ALTER PUBLICATION name RENAME TO new_name
```

## DESCRIPTION
The command ALTER PUBLICATION can change the attributes of a publication.

The first three variants change which tables are part of the publication. The SET TABLE clause will replace the list of tables in the publication with the specified one. The ADD TABLE and DROP TABLE clauses will add and remove one or more tables from the publication. Note that adding tables to a publication that is already subscribed to will require a ALTER SUBSCRIPTION ... REFRESH PUBLICATION action on the subscribing side in order to become effective.

The fourth variant of this command listed in the synopsis can change all of the publication properties specified in CREATE PUBLICATION (CREATE_PUBLICATION(7)). Properties not mentioned in the command retain their previous settings.

The remaining variants change the owner and the name of the publication.

You must own the publication to use ALTER PUBLICATION. Adding a table to a publication additionally requires owning that table. To alter the owner, you must also be a direct or indirect member of the new owning role. The new owner must have CREATE privilege on the database. Also, the new owner of a FOR ALL TABLES publication must be a superuser. However, a superuser can change the ownership of a publication regardless of these restrictions.

## PARAMETERS
name

The name of an existing publication whose definition is to be altered.

table_name

Name of an existing table. If ONLY is specified before the table name, only that table is affected. If ONLY is not specified, the table and all its descendant tables (if any) are affected. Optionally, * can be specified after the table name to explicitly indicate that descendant tables are included.

SET ( publication_parameter [= value] [, ... ] )

This clause alters publication parameters originally set by CREATE PUBLICATION (CREATE_PUBLICATION(7)). See there for more information.

new_owner

The user name of the new owner of the publication.

new_name

The new name for the publication.

## EXAMPLES
Change the publication to publish only deletes and updates:

```
ALTER PUBLICATION noinsert SET (publish = 'update, delete');
```

Add some tables to the publication:

```
ALTER PUBLICATION mypublication ADD TABLE users, departments;
```

## COMPATIBILITY
ALTER PUBLICATION is a PostgreSQL extension.

## SEE ALSO
CREATE PUBLICATION (CREATE_PUBLICATION(7)), DROP PUBLICATION (DROP_PUBLICATION(7)), CREATE SUBSCRIPTION (CREATE_SUBSCRIPTION(7)), ALTER SUBSCRIPTION (ALTER_SUBSCRIPTION(7))


title: ALTER_ROLE(7)

summary: change a database role

text:
# ALTER_ROLE(7)

## NAME
ALTER_ROLE - change a database role

## SYNOPSIS

```
ALTER ROLE role_specification [ WITH ] option [ ... ]
where option can be:

      SUPERUSER | NOSUPERUSER

    | CREATEDB | NOCREATEDB

    | CREATEROLE | NOCREATEROLE

    | INHERIT | NOINHERIT

    | LOGIN | NOLOGIN

    | REPLICATION | NOREPLICATION

    | BYPASSRLS | NOBYPASSRLS

    | CONNECTION LIMIT connlimit

    | [ ENCRYPTED ] PASSWORD 'password' | PASSWORD NULL

    | VALID UNTIL 'timestamp'
ALTER ROLE name RENAME TO new_name
ALTER ROLE { role_specification | ALL } [ IN DATABASE database_name ] SET configuration_parameter { TO | = } { value | DEFAULT }
ALTER ROLE { role_specification | ALL } [ IN DATABASE database_name ] SET configuration_parameter FROM CURRENT
ALTER ROLE { role_specification | ALL } [ IN DATABASE database_name ] RESET configuration_parameter
ALTER ROLE { role_specification | ALL } [ IN DATABASE database_name ] RESET ALL
where role_specification can be:

    role_name

  | CURRENT_ROLE

  | CURRENT_USER

  | SESSION_USER
```

## DESCRIPTION
ALTER ROLE changes the attributes of a PostgreSQL role.

The first variant of this command listed in the synopsis can change many of the role attributes that can be specified in CREATE ROLE. (All the possible attributes are covered, except that there are no options for adding or removing memberships; use GRANT and REVOKE for that.) Attributes not mentioned in the command retain their previous settings. Database superusers can change any of these settings for any role. Roles having CREATEROLE privilege can change any of these settings except SUPERUSER, REPLICATION, and BYPASSRLS; but only for non-superuser and non-replication roles. Ordinary roles can only change their own password.

The second variant changes the name of the role. Database superusers can rename any role. Roles having CREATEROLE privilege can rename non-superuser roles. The current session user cannot be renamed. (Connect as a different user if you need to do that.) Because MD5-encrypted passwords use the role name as cryptographic salt, renaming a role clears its password if the password is MD5-encrypted.

The remaining variants change a role's session default for a configuration variable, either for all databases or, when the IN DATABASE clause is specified, only for sessions in the named database. If ALL is specified instead of a role name, this changes the setting for all roles. Using ALL with IN DATABASE is effectively the same as using the command ALTER DATABASE ... SET ....

Whenever the role subsequently starts a new session, the specified value becomes the session default, overriding whatever setting is present in postgresql.conf or has been received from the postgres command line. This only happens at login time; executing SET ROLE or SET SESSION AUTHORIZATION does not cause new configuration values to be set. Settings set for all databases are overridden by database-specific settings attached to a role. Settings for specific databases or specific roles override settings for all roles.

Superusers can change anyone's session defaults. Roles having CREATEROLE privilege can change defaults for non-superuser roles. Ordinary roles can only set defaults for themselves. Certain configuration variables cannot be set this way, or can only be set if a superuser issues the command. Only superusers can change a setting for all roles in all databases.

## PARAMETERS
name

The name of the role whose attributes are to be altered.

CURRENT_ROLE

CURRENT_USER

Alter the current user instead of an explicitly identified role.

SESSION_USER

Alter the current session user instead of an explicitly identified role.

SUPERUSER

NOSUPERUSER

CREATEDB

NOCREATEDB

CREATEROLE

NOCREATEROLE

INHERIT

NOINHERIT

LOGIN

NOLOGIN

REPLICATION

NOREPLICATION

BYPASSRLS

NOBYPASSRLS

CONNECTION LIMIT connlimit

[ ENCRYPTED ] PASSWORD 'password'

PASSWORD NULL

VALID UNTIL 'timestamp'

These clauses alter attributes originally set by CREATE ROLE. For more information, see the CREATE ROLE reference page.

new_name

The new name of the role.

database_name

The name of the database the configuration variable should be set in.

configuration_parameter

value

Set this role's session default for the specified configuration parameter to the given value. If value is DEFAULT or, equivalently, RESET is used, the role-specific variable setting is removed, so the role will inherit the system-wide default setting in new sessions. Use RESET ALL to clear all role-specific settings. SET FROM CURRENT saves the session's current value of the parameter as the role-specific value. If IN DATABASE is specified, the configuration parameter is set or removed for the given role and database only. Role-specific variable settings take effect only at login; SET ROLE and SET SESSION AUTHORIZATION do not process role-specific variable settings.

See SET(7) and Chapter 20 for more information about allowed parameter names and values.

## NOTES
Use CREATE ROLE to add new roles, and DROP ROLE to remove a role.

ALTER ROLE cannot change a role's memberships. Use GRANT and REVOKE to do that.

Caution must be exercised when specifying an unencrypted password with this command. The password will be transmitted to the server in cleartext, and it might also be logged in the client's command history or the server log. psql(1) contains a command \password that can be used to change a role's password without exposing the cleartext password.

It is also possible to tie a session default to a specific database rather than to a role; see ALTER DATABASE (ALTER_DATABASE(7)). If there is a conflict, database-role-specific settings override role-specific ones, which in turn override database-specific ones.

## EXAMPLES
Change a role's password:

```
ALTER ROLE davide WITH PASSWORD 'hu8jmn3';
```

Remove a role's password:

```
ALTER ROLE davide WITH PASSWORD NULL;
```

Change a password expiration date, specifying that the password should expire at midday on 4th May 2015 using the time zone which is one hour ahead of UTC:

```
ALTER ROLE chris VALID UNTIL 'May 4 12:00:00 2015 +1';
```

Make a password valid forever:

```
ALTER ROLE fred VALID UNTIL 'infinity';
```

Give a role the ability to manage other roles and create new databases:

```
ALTER ROLE miriam CREATEROLE CREATEDB;
```

Give a role a non-default setting of the maintenance_work_mem parameter:

```
ALTER ROLE worker_bee SET maintenance_work_mem = 100000;
```

Give a role a non-default, database-specific setting of the client_min_messages parameter:

```
ALTER ROLE fred IN DATABASE devel SET client_min_messages = DEBUG;
```

## COMPATIBILITY
The ALTER ROLE statement is a PostgreSQL extension.

## SEE ALSO
CREATE ROLE (CREATE_ROLE(7)), DROP ROLE (DROP_ROLE(7)), ALTER DATABASE (ALTER_DATABASE(7)), SET(7)


title: ALTER_ROUTINE(7)

summary: change the definition of a routine

text:
# ALTER_ROUTINE(7)

## NAME
ALTER_ROUTINE - change the definition of a routine

## SYNOPSIS

```
ALTER ROUTINE name [ ( [ [ argmode ] [ argname ] argtype [, ...] ] ) ]

    action [ ... ] [ RESTRICT ]
ALTER ROUTINE name [ ( [ [ argmode ] [ argname ] argtype [, ...] ] ) ]

    RENAME TO new_name
ALTER ROUTINE name [ ( [ [ argmode ] [ argname ] argtype [, ...] ] ) ]

    OWNER TO { new_owner | CURRENT_ROLE | CURRENT_USER | SESSION_USER }
ALTER ROUTINE name [ ( [ [ argmode ] [ argname ] argtype [, ...] ] ) ]

    SET SCHEMA new_schema
ALTER ROUTINE name [ ( [ [ argmode ] [ argname ] argtype [, ...] ] ) ]

    [ NO ] DEPENDS ON EXTENSION extension_name
where action is one of:

    IMMUTABLE | STABLE | VOLATILE

    [ NOT ] LEAKPROOF

    [ EXTERNAL ] SECURITY INVOKER | [ EXTERNAL ] SECURITY DEFINER

    PARALLEL { UNSAFE | RESTRICTED | SAFE }

    COST execution_cost

    ROWS result_rows

    SET configuration_parameter { TO | = } { value | DEFAULT }

    SET configuration_parameter FROM CURRENT

    RESET configuration_parameter

    RESET ALL
```

## DESCRIPTION
ALTER ROUTINE changes the definition of a routine, which can be an aggregate function, a normal function, or a procedure. See under ALTER AGGREGATE (ALTER_AGGREGATE(7)), ALTER FUNCTION (ALTER_FUNCTION(7)), and ALTER PROCEDURE (ALTER_PROCEDURE(7)) for the description of the parameters, more examples, and further details.

## EXAMPLES
To rename the routine foo for type integer to foobar:

```
ALTER ROUTINE foo(integer) RENAME TO foobar;
```

This command will work independent of whether foo is an aggregate, function, or procedure.

## COMPATIBILITY
This statement is partially compatible with the ALTER ROUTINE statement in the SQL standard. See under ALTER FUNCTION (ALTER_FUNCTION(7)) and ALTER PROCEDURE (ALTER_PROCEDURE(7)) for more details. Allowing routine names to refer to aggregate functions is a PostgreSQL extension.

## SEE ALSO
ALTER AGGREGATE (ALTER_AGGREGATE(7)), ALTER FUNCTION (ALTER_FUNCTION(7)), ALTER PROCEDURE (ALTER_PROCEDURE(7)), DROP ROUTINE (DROP_ROUTINE(7))

Note that there is no CREATE ROUTINE command.


title: ALTER_RULE(7)

summary: change the definition of a rule

text:
# ALTER_RULE(7)

## NAME
ALTER_RULE - change the definition of a rule

## SYNOPSIS

```
ALTER RULE name ON table_name RENAME TO new_name
```

## DESCRIPTION
ALTER RULE changes properties of an existing rule. Currently, the only available action is to change the rule's name.

To use ALTER RULE, you must own the table or view that the rule applies to.

## PARAMETERS
name

The name of an existing rule to alter.

table_name

The name (optionally schema-qualified) of the table or view that the rule applies to.

new_name

The new name for the rule.

## EXAMPLES
To rename an existing rule:

```
ALTER RULE notify_all ON emp RENAME TO notify_me;
```

## COMPATIBILITY
ALTER RULE is a PostgreSQL language extension, as is the entire query rewrite system.

## SEE ALSO
CREATE RULE (CREATE_RULE(7)), DROP RULE (DROP_RULE(7))


title: ALTER_SCHEMA(7)

summary: change the definition of a schema

text:
# ALTER_SCHEMA(7)

## NAME
ALTER_SCHEMA - change the definition of a schema

## SYNOPSIS

```
ALTER SCHEMA name RENAME TO new_name
ALTER SCHEMA name OWNER TO { new_owner | CURRENT_ROLE | CURRENT_USER | SESSION_USER }
```

## DESCRIPTION
ALTER SCHEMA changes the definition of a schema.

You must own the schema to use ALTER SCHEMA. To rename a schema you must also have the CREATE privilege for the database. To alter the owner, you must also be a direct or indirect member of the new owning role, and you must have the CREATE privilege for the database. (Note that superusers have all these privileges automatically.)

## PARAMETERS
name

The name of an existing schema.

new_name

The new name of the schema. The new name cannot begin with pg_, as such names are reserved for system schemas.

new_owner

The new owner of the schema.

## COMPATIBILITY
There is no ALTER SCHEMA statement in the SQL standard.

## SEE ALSO
CREATE SCHEMA (CREATE_SCHEMA(7)), DROP SCHEMA (DROP_SCHEMA(7))


title: ALTER_SEQUENCE(7)

text:
# ALTER_SEQUENCE(7)

## NAME
ALTER_SEQUENCE - change the definition of a sequence generator

## SYNOPSIS

```
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 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
```

## DESCRIPTION
ALTER SEQUENCE changes the parameters of an existing sequence generator. 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. To alter the owner, you must also be a direct or indirect member of the new owning role, and that role must 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.)

## PARAMETERS
name

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

IF EXISTS

Do not throw an error if the sequence does not exist. A notice is issued in this case.

data_type

The optional clause AS data_type changes the data type of the sequence. Valid types are smallint, integer, and bigint. 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 do not fit into the new data type, an error will be generated.

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 maintained.

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 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 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 of the maximum value of the data type 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 START WITH start changes the recorded start value of the sequence. This has no effect on the current sequence value; it simply sets the value that future ALTER SEQUENCE RESTART commands will use.

restart

The optional clause RESTART [ WITH restart ] changes the current value of the sequence. This is similar to calling the setval function with is_called = false: the specified value will be returned by the next call of nextval. Writing RESTART with no restart value is equivalent to supplying the start value that was recorded by CREATE SEQUENCE or last set by ALTER SEQUENCE START WITH. 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.

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 can 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.

OWNED BY table_name.column_name

OWNED BY NONE

The OWNED BY option 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. Specifying OWNED BY NONE removes any existing association, making the sequence “free-standing”.

new_owner

The user name of the new owner of the sequence.

new_name

The new name for the sequence.

new_schema

The new schema for the sequence.

## NOTES
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 will be affected immediately.

ALTER SEQUENCE does not affect the currval status for the sequence. (Before PostgreSQL 8.3, it sometimes did.)

ALTER SEQUENCE blocks concurrent nextval, currval, lastval, and setval calls.

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.

## EXAMPLES
Restart a sequence called serial, at 105:

```
ALTER SEQUENCE serial RESTART WITH 105;
```

## COMPATIBILITY
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.

## SEE ALSO
CREATE SEQUENCE (CREATE_SEQUENCE(7)), DROP SEQUENCE (DROP_SEQUENCE(7))


title: ALTER_SERVER(7)

text:
# ALTER_SERVER(7)

## NAME
ALTER_SERVER - change the definition of a foreign server

## SYNOPSIS

```
ALTER SERVER name [ VERSION 'new_version' ]

    [ OPTIONS ( [ ADD | SET | DROP ] option ['value'] [, ... ] ) ]
ALTER SERVER name OWNER TO { new_owner | CURRENT_ROLE | CURRENT_USER | SESSION_USER }
ALTER SERVER name RENAME TO new_name
```

## DESCRIPTION
ALTER SERVER changes the definition of a foreign server. The first form changes the server version string or the generic options of the server (at least one clause is required). The second form changes the owner of the server.

To alter the server you must be the owner of the server. Additionally to alter the owner, you must own the server and also be a direct or indirect member of the new owning role, and you must have USAGE privilege on the server's foreign-data wrapper. (Note that superusers satisfy all these criteria automatically.)

## PARAMETERS
name

The name of an existing server.

new_version

New server version.

OPTIONS ( [ ADD | SET | DROP ] option ['value'] [, ... ] )

Change options for the server. ADD, SET, and DROP specify the action to be performed. ADD is assumed if no operation is explicitly specified. Option names must be unique; names and values are also validated using the server's foreign-data wrapper library.

new_owner

The user name of the new owner of the foreign server.

new_name

The new name for the foreign server.

## EXAMPLES
Alter server foo, add connection options:

```
ALTER SERVER foo OPTIONS (host 'foo', dbname 'foodb');
```

Alter server foo, change version, change host option:

```
ALTER SERVER foo VERSION '8.4' OPTIONS (SET host 'baz');
```

## COMPATIBILITY
ALTER SERVER conforms to ISO/IEC 9075-9 (SQL/MED). The OWNER TO and RENAME forms are PostgreSQL extensions.

## SEE ALSO
CREATE SERVER (CREATE_SERVER(7)), DROP SERVER (DROP_SERVER(7))


title: ALTER_STATISTICS(7)

text:
# ALTER_STATISTICS(7)

## NAME
ALTER_STATISTICS - change the definition of an extended statistics object

## SYNOPSIS

```
ALTER STATISTICS name OWNER TO { new_owner | CURRENT_ROLE | CURRENT_USER | SESSION_USER }
ALTER STATISTICS name RENAME TO new_name
ALTER STATISTICS name SET SCHEMA new_schema
ALTER STATISTICS name SET STATISTICS new_target
```

## DESCRIPTION
ALTER STATISTICS changes the parameters of an existing extended statistics object. Any parameters not specifically set in the ALTER STATISTICS command retain their prior settings.

You must own the statistics object to use ALTER STATISTICS. To change a statistics object's schema, you must also have CREATE privilege on the new schema. To alter the owner, you must also be a direct or indirect member of the new owning role, and that role must have CREATE privilege on the statistics object's schema. (These restrictions enforce that altering the owner doesn't do anything you couldn't do by dropping and recreating the statistics object. However, a superuser can alter ownership of any statistics object anyway.)

## PARAMETERS
name

The name (optionally schema-qualified) of the statistics object to be altered.

new_owner

The user name of the new owner of the statistics object.

new_name

The new name for the statistics object.

new_schema

The new schema for the statistics object.

new_target

The statistic-gathering target for this statistics object for subsequent ANALYZE operations. The target can be set in the range 0 to 10000; alternatively, set it to -1 to revert to using the maximum of the statistics target of the referenced columns, if set, or the system default statistics target (default_statistics_target). For more information on the use of statistics by the PostgreSQL query planner, refer to Section 14.2.

## COMPATIBILITY
There is no ALTER STATISTICS command in the SQL standard.

## SEE ALSO
CREATE STATISTICS (CREATE_STATISTICS(7)), DROP STATISTICS (DROP_STATISTICS(7))


title: ALTER_SUBSCRIPTION(7)

summary: change the definition of a subscription

text:
# ALTER_SUBSCRIPTION(7)

## NAME
ALTER_SUBSCRIPTION - change the definition of a subscription

## SYNOPSIS

```
ALTER SUBSCRIPTION name CONNECTION 'conninfo'
ALTER SUBSCRIPTION name SET PUBLICATION publication_name [, ...] [ WITH ( publication_option [= value] [, ... ] ) ]
ALTER SUBSCRIPTION name ADD PUBLICATION publication_name [, ...] [ WITH ( publication_option [= value] [, ... ] ) ]
ALTER SUBSCRIPTION name DROP PUBLICATION publication_name [, ...] [ WITH ( publication_option [= value] [, ... ] ) ]
ALTER SUBSCRIPTION name REFRESH PUBLICATION [ WITH ( refresh_option [= value] [, ... ] ) ]
ALTER SUBSCRIPTION name ENABLE
ALTER SUBSCRIPTION name DISABLE
ALTER SUBSCRIPTION name SET ( subscription_parameter [= value] [, ... ] )
ALTER SUBSCRIPTION name OWNER TO { new_owner | CURRENT_ROLE | CURRENT_USER | SESSION_USER }
ALTER SUBSCRIPTION name RENAME TO new_name
```

## DESCRIPTION
ALTER SUBSCRIPTION can change most of the subscription properties that can be specified in CREATE SUBSCRIPTION (CREATE_SUBSCRIPTION(7)).

You must own the subscription to use ALTER SUBSCRIPTION. To alter the owner, you must also be a direct or indirect member of the new owning role. The new owner has to be a superuser. (Currently, all subscription owners must be superusers, so the owner checks will be bypassed in practice. But this might change in the future.)

When refreshing a publication we remove the relations that are no longer part of the publication and we also remove the table synchronization slots if there are any. It is necessary to remove these slots so that the resources allocated for the subscription on the remote host are released. If due to network breakdown or some other error, PostgreSQL is unable to remove the slots, an ERROR will be reported. To proceed in this situation, the user either needs to retry the operation or disassociate the slot from the subscription and drop the subscription as explained in DROP SUBSCRIPTION (DROP_SUBSCRIPTION(7)).

Commands ALTER SUBSCRIPTION ... REFRESH PUBLICATION and ALTER SUBSCRIPTION ... {SET|ADD|DROP} PUBLICATION ... with refresh option as true cannot be executed inside a transaction block.

## PARAMETERS
name

The name of a subscription whose properties are to be altered.

CONNECTION 'conninfo'

This clause alters the connection property originally set by CREATE SUBSCRIPTION (CREATE_SUBSCRIPTION(7)). See there for more information.

SET PUBLICATION publication_name

ADD PUBLICATION publication_name

DROP PUBLICATION publication_name

Changes the list of subscribed publications. SET replaces the entire list of publications with a new list, ADD adds additional publications to the list of publications, and DROP removes the publications from the list of publications. See CREATE SUBSCRIPTION (CREATE_SUBSCRIPTION(7)) for more information. By default, this command will also act like REFRESH PUBLICATION. publication_option specifies additional options for this operation. The supported options are:

refresh (boolean)

When false, the command will not try to refresh table information. REFRESH PUBLICATION should then be executed separately. The default is true.

Additionally, the options described under REFRESH PUBLICATION may be specified, to control the implicit refresh operation.

REFRESH PUBLICATION

Fetch missing table information from publisher. This will start replication of tables that were added to the subscribed-to publications since the last invocation of REFRESH PUBLICATION or since CREATE SUBSCRIPTION. refresh_option specifies additional options for the refresh operation. The supported options are:

copy_data (boolean)

Specifies whether the existing data in the publications that are being subscribed to should be copied once the replication starts. The default is true. (Previously subscribed tables are not copied.)

ENABLE

Enables the previously disabled subscription, starting the logical replication worker at the end of transaction.

DISABLE

Disables the running subscription, stopping the logical replication worker at the end of transaction.

SET ( subscription_parameter [= value] [, ... ] )

This clause alters parameters originally set by CREATE SUBSCRIPTION (CREATE_SUBSCRIPTION(7)). See there for more information. The parameters that can be altered are slot_name, synchronous_commit, binary, and streaming.

new_owner

The user name of the new owner of the subscription.

new_name

The new name for the subscription.

## EXAMPLES
Change the publication subscribed by a subscription to insert_only:

```
ALTER SUBSCRIPTION mysub SET PUBLICATION insert_only;
```

Disable (stop) the subscription:

```
ALTER SUBSCRIPTION mysub DISABLE;
```

## COMPATIBILITY
ALTER SUBSCRIPTION is a PostgreSQL extension.

## SEE ALSO
CREATE SUBSCRIPTION (CREATE_SUBSCRIPTION(7)), DROP SUBSCRIPTION (DROP_SUBSCRIPTION(7)), CREATE PUBLICATION (CREATE_PUBLICATION(7)), ALTER PUBLICATION (ALTER_PUBLICATION(7))


title: ALTER_SYSTEM(7)

summary: change a server configuration parameter

text:
# ALTER_SYSTEM(7)

## NAME
ALTER_SYSTEM - change a server configuration parameter

## SYNOPSIS

```
ALTER SYSTEM SET configuration_parameter { TO | = } { value [, ...] | DEFAULT }
ALTER SYSTEM RESET configuration_parameter
ALTER SYSTEM RESET ALL
```

## DESCRIPTION
ALTER SYSTEM is used for changing server configuration parameters across the entire database cluster. It can be more convenient than the traditional method of manually editing the postgresql.conf file. ALTER SYSTEM writes the given parameter setting to the postgresql.auto.conf file, which is read in addition to postgresql.conf. Setting a parameter to DEFAULT, or using the RESET variant, removes that configuration entry from the postgresql.auto.conf file. Use RESET ALL to remove all such configuration entries.

Values set with ALTER SYSTEM will be effective after the next server configuration reload, or after the next server restart in the case of parameters that can only be changed at server start. A server configuration reload can be commanded by calling the SQL function pg_reload_conf(), running pg_ctl reload, or sending a SIGHUP signal to the main server process.

Only superusers can use ALTER SYSTEM. Also, since this command acts directly on the file system and cannot be rolled back, it is not allowed inside a transaction block or function.

## PARAMETERS
configuration_parameter

Name of a settable configuration parameter. Available parameters are documented in Chapter 20.

value

New value of the parameter. Values can be specified as string constants, identifiers, numbers, or comma-separated lists of these, as appropriate for the particular parameter. Values that are neither numbers nor valid identifiers must be quoted. DEFAULT can be written to specify removing the parameter and its value from postgresql.auto.conf. For some list-accepting parameters, quoted values will produce double-quoted output to preserve whitespace and commas; for others, double-quotes must be used inside single-quoted strings to get this effect.

## NOTES
This command can't be used to set data_directory, nor parameters that are not allowed in postgresql.conf (e.g., preset options).

See Section 20.1 for other ways to set the parameters.

## EXAMPLES
Set the wal_level:

```
ALTER SYSTEM SET wal_level = replica;
```

Undo that, restoring whatever setting was effective in postgresql.conf:

```
ALTER SYSTEM RESET wal_level;
```

## COMPATIBILITY
The ALTER SYSTEM statement is a PostgreSQL extension.

## SEE ALSO
SET(7), SHOW(7)


title: ALTER_TABLE(7)

summary: change the definition of a table

text:
# ALTER_TABLE(7)

## NAME
ALTER_TABLE - change the definition of a table

## SYNOPSIS

```
ALTER TABLE [ IF EXISTS ] [ ONLY ] name [ * ]

    action [, ... ]
ALTER TABLE [ IF EXISTS ] [ ONLY ] name [ * ]

    RENAME [ COLUMN ] column_name TO new_column_name
ALTER TABLE [ IF EXISTS ] [ ONLY ] name [ * ]

    RENAME CONSTRAINT constraint_name TO new_constraint_name
ALTER TABLE [ IF EXISTS ] name

    RENAME TO new_name
ALTER TABLE [ IF EXISTS ] name

    SET SCHEMA new_schema
ALTER TABLE ALL IN TABLESPACE name [ OWNED BY role_name [, ... ] ]

    SET TABLESPACE new_tablespace [ NOWAIT ]
ALTER TABLE [ IF EXISTS ] name

    ATTACH PARTITION partition_name { FOR VALUES partition_bound_spec | DEFAULT }
ALTER TABLE [ IF EXISTS ] name

    DETACH PARTITION partition_name [ CONCURRENTLY | FINALIZE ]
where action is one of:

    ADD [ COLUMN ] [ IF NOT EXISTS ] column_name data_type [ COLLATE collation ] [ column_constraint [ ... ] ]

    DROP [ COLUMN ] [ IF EXISTS ] column_name [ RESTRICT | CASCADE ]

    ALTER [ COLUMN ] column_name [ SET DATA ] TYPE data_type [ COLLATE collation ] [ USING expression ]

    ALTER [ COLUMN ] column_name SET DEFAULT expression

    ALTER [ COLUMN ] column_name DROP DEFAULT

    ALTER [ COLUMN ] column_name { SET | DROP } NOT NULL

    ALTER [ COLUMN ] column_name DROP EXPRESSION [ IF EXISTS ]

    ALTER [ COLUMN ] column_name ADD GENERATED { ALWAYS | BY DEFAULT } AS IDENTITY [ ( sequence_options ) ]

    ALTER [ COLUMN ] column_name { SET GENERATED { ALWAYS | BY DEFAULT } | SET sequence_option | RESTART [ [ WITH ] restart ] } [...]

    ALTER [ COLUMN ] column_name DROP IDENTITY [ IF EXISTS ]

    ALTER [ COLUMN ] column_name SET STATISTICS integer

    ALTER [ COLUMN ] column_name SET ( attribute_option = value [, ... ] )

    ALTER [ COLUMN ] column_name RESET ( attribute_option [, ... ] )

    ALTER [ COLUMN ] column_name SET STORAGE { PLAIN | EXTERNAL | EXTENDED | MAIN }

    ALTER [ COLUMN ] column_name SET COMPRESSION compression_method

    ADD table_constraint [ NOT VALID ]

    ADD table_constraint_using_index

    ALTER CONSTRAINT constraint_name [ DEFERRABLE | NOT DEFERRABLE ] [ INITIALLY DEFERRED | INITIALLY IMMEDIATE ]

    VALIDATE CONSTRAINT constraint_name

    DROP CONSTRAINT [ IF EXISTS ]  constraint_name [ RESTRICT | CASCADE ]

    DISABLE TRIGGER [ trigger_name | ALL | USER ]

    ENABLE TRIGGER [ trigger_name | ALL | USER ]

    ENABLE REPLICA TRIGGER trigger_name

    ENABLE ALWAYS TRIGGER trigger_name

    DISABLE RULE rewrite_rule_name

    ENABLE RULE rewrite_rule_name

    ENABLE REPLICA RULE rewrite_rule_name

    ENABLE ALWAYS RULE rewrite_rule_name

    DISABLE ROW LEVEL SECURITY

    ENABLE ROW LEVEL SECURITY

    FORCE ROW LEVEL SECURITY

    NO FORCE ROW LEVEL SECURITY

    CLUSTER ON index_name

    SET WITHOUT CLUSTER

    SET WITHOUT OIDS

    SET TABLESPACE new_tablespace

    SET { LOGGED | UNLOGGED }

    SET ( storage_parameter [= value] [, ... ] )

    RESET ( storage_parameter [, ... ] )

    INHERIT parent_table

    NO INHERIT parent_table

    OF type_name

    NOT OF

    OWNER TO { new_owner | CURRENT_ROLE | CURRENT_USER | SESSION_USER }

    REPLICA IDENTITY { DEFAULT | USING INDEX index_name | FULL | NOTHING }
and partition_bound_spec is:
IN ( partition_bound_expr [, ...] ) |
FROM ( { partition_bound_expr | MINVALUE | MAXVALUE } [, ...] )

  TO ( { partition_bound_expr | MINVALUE | MAXVALUE } [, ...] ) |
WITH ( MODULUS numeric_literal, REMAINDER numeric_literal )
and column_constraint is:
[ CONSTRAINT constraint_name ]
{ NOT NULL |

  NULL |

  CHECK ( expression ) [ NO INHERIT ] |

  DEFAULT default_expr |

  GENERATED ALWAYS AS ( generation_expr ) STORED |

  GENERATED { ALWAYS | BY DEFAULT } AS IDENTITY [ ( sequence_options ) ] |

  UNIQUE index_parameters |

  PRIMARY KEY index_parameters |

  REFERENCES reftable [ ( refcolumn ) ] [ MATCH FULL | MATCH PARTIAL | MATCH SIMPLE ]

    [ ON DELETE referential_action ] [ ON UPDATE referential_action ] }
[ DEFERRABLE | NOT DEFERRABLE ] [ INITIALLY DEFERRED | INITIALLY IMMEDIATE ]
and table_constraint is:
[ CONSTRAINT constraint_name ]
{ CHECK ( expression ) [ NO INHERIT ] |

  UNIQUE ( column_name [, ... ] ) index_parameters |

  PRIMARY KEY ( column_name [, ... ] ) index_parameters |

  EXCLUDE [ USING index_method ] ( exclude_element WITH operator [, ... ] ) index_parameters [ WHERE ( predicate ) ] |

  FOREIGN KEY ( column_name [, ... ] ) REFERENCES reftable [ ( refcolumn [, ... ] ) ]

    [ MATCH FULL | MATCH PARTIAL | MATCH SIMPLE ] [ ON DELETE referential_action ] [ ON UPDATE referential_action ] }
[ DEFERRABLE | NOT DEFERRABLE ] [ INITIALLY DEFERRED | INITIALLY IMMEDIATE ]
and table_constraint_using_index is:

    [ CONSTRAINT constraint_name ]

    { UNIQUE | PRIMARY KEY } USING INDEX index_name

    [ DEFERRABLE | NOT DEFERRABLE ] [ INITIALLY DEFERRED | INITIALLY IMMEDIATE ]
index_parameters in UNIQUE, PRIMARY KEY, and EXCLUDE constraints are:
[ INCLUDE ( column_name [, ... ] ) ]
[ WITH ( storage_parameter [= value] [, ... ] ) ]
[ USING INDEX TABLESPACE tablespace_name ]
exclude_element in an EXCLUDE constraint is:
{ column_name | ( expression ) } [ COLLATE collation ] [ opclass [ ( opclass_parameter = value [, ... ] ) ] ] [ ASC | DESC ] [ NULLS { FIRST | LAST } ]
```

## DESCRIPTION
ALTER TABLE changes the definition of an existing table. There are several subforms described below. Note that the lock level required may differ for each subform. An ACCESS EXCLUSIVE lock is acquired unless explicitly noted. When multiple subcommands are given, the lock acquired will be the strictest one required by any subcommand.

ADD [ COLUMN ] [ IF NOT EXISTS ]

This form adds a new column to the table, using the same syntax as CREATE TABLE. If IF NOT EXISTS is specified and a column already exists with this name, no error is thrown.

DROP [ COLUMN ] [ IF EXISTS ]

This form drops a column from a table. Indexes and table constraints involving the column will be automatically dropped as well. Multivariate statistics referencing the dropped column will also be removed if the removal of the column would cause the statistics to contain data for only a single column. You will need to say CASCADE if anything outside the table depends on the column, for example, foreign key references or views. If IF EXISTS is specified and the column does not exist, no error is thrown. In this case a notice is issued instead.

SET DATA TYPE

This form changes the type of a column of a table. Indexes and simple table constraints involving the column will be automatically converted to use the new column type by reparsing the originally supplied expression. The optional COLLATE clause specifies a collation for the new column; if omitted, the collation is the default for the new column type. The optional USING clause specifies how to compute the new column value from the old; if omitted, the default conversion is the same as an assignment cast from old data type to new. A USING clause must be provided if there is no implicit or assignment cast from old to new type.

SET/DROP DEFAULT

These forms set or remove the default value for a column (where removal is equivalent to setting the default value to NULL). The new default value will only apply in subsequent INSERT or UPDATE commands; it does not cause rows already in the table to change.

SET/DROP NOT NULL

These forms change whether a column is marked to allow null values or to reject null values. SET NOT NULL may only be applied to a column provided none of the records in the table contain a NULL value for the column. Ordinarily this is checked during the ALTER TABLE by scanning the entire table; however, if a valid CHECK constraint exists (and is not dropped in the same command) which proves no NULL can exist, then the table scan is skipped.

If this table is a partition, one cannot perform DROP NOT NULL on a column if it is marked NOT NULL in the parent table. To drop the NOT NULL constraint from all the partitions, perform DROP NOT NULL on the parent table. Even if there is no NOT NULL constraint on the parent, such a constraint can still be added to individual partitions, if desired; that is, the children can disallow nulls even if the parent allows them, but not the other way around.

DROP EXPRESSION [ IF EXISTS ]

This form turns a stored generated column into a normal base column. Existing data in the columns is retained, but future changes will no longer apply the generation expression. If DROP EXPRESSION IF EXISTS is specified and the column is not a stored generated column, no error is thrown. In this case a notice is issued instead.

ADD GENERATED { ALWAYS | BY DEFAULT } AS IDENTITY

SET GENERATED { ALWAYS | BY DEFAULT }

DROP IDENTITY [ IF EXISTS ]

These forms change whether a column is an identity column or change the generation attribute of an existing identity column. See CREATE TABLE for details. Like SET DEFAULT, these forms only affect the behavior of subsequent INSERT and UPDATE commands; they do not cause rows already in the table to change. If DROP IDENTITY IF EXISTS is specified and the column is not an identity column, no error is thrown. In this case a notice is issued instead.

SET sequence_option

RESTART

These forms alter the sequence that underlies an existing identity column. sequence_option is an option supported by ALTER SEQUENCE such as INCREMENT BY.

SET STATISTICS

This form sets the per-column statistics-gathering target for subsequent ANALYZE operations. The target can be set in the range 0 to 10000; alternatively, set it to -1 to revert to using the system default statistics target (default_statistics_target). For more information on the use of statistics by the PostgreSQL query planner, refer to Section 14.2. SET STATISTICS acquires a SHARE UPDATE EXCLUSIVE lock.

SET ( attribute_option = value [, ... ] )

RESET ( attribute_option [, ... ] )

This form sets or resets per-attribute options. Currently, the only defined per-attribute options are n_distinct and n_distinct_inherited, which override the number-of-distinct-values estimates made by subsequent ANALYZE operations. n_distinct affects the statistics for the table itself, while n_distinct_inherited affects the statistics gathered for the table plus its inheritance children, and for the statistics gathered for partitioned tables. When the value specified is a positive value, the query planner will assume that the column contains exactly the specified number of distinct nonnull values. Fractional values may also be specified by using values below 0 and above or equal to -1. This instructs the query planner to estimate the number of distinct values by multiplying the absolute value of the specified number by the estimated number of rows in the table. For example, a value of -1 implies that all values in the column are distinct, while a value of -0.5 implies that each value appears twice on average. This can be useful when the size of the table changes over time. For more information on the use of statistics by the PostgreSQL query planner, refer to Section 14.2. Changing per-attribute options acquires a SHARE UPDATE EXCLUSIVE lock.

SET STORAGE

This form sets the storage mode for a column. This controls whether this column is held inline or in a secondary TOAST table, and whether the data should be compressed or not. PLAIN must be used for fixed-length values such as integer and is inline, uncompressed. MAIN is for inline, compressible data. EXTERNAL is for external, uncompressed data, and EXTENDED is for external, compressed data. EXTENDED is the default for most data types that support non-PLAIN storage. Use of EXTERNAL will make substring operations on very large text and bytea values run faster, at the penalty of increased storage space. Note that SET STORAGE doesn't itself change anything in the table, it just sets the strategy to be pursued during future table updates. See Section 70.2 for more information.

SET COMPRESSION compression_method

This form sets the compression method for a column, determining how values inserted in future will be compressed (if the storage mode permits compression at all). This does not cause the table to be rewritten, so existing data may still be compressed with other compression methods. If the table is restored with pg_restore, then all values are rewritten with the configured compression method. However, when data is inserted from another relation (for example, by INSERT ... SELECT), values from the source table are not necessarily detoasted, so any previously compressed data may retain its existing compression method, rather than being recompressed with the compression method of the target column. The supported compression methods are pglz and lz4. (lz4 is available only if --with-lz4 was used when building PostgreSQL.) In addition, compression_method can be default, which selects the default behavior of consulting the default_toast_compression setting at the time of data insertion to determine the method to use.

ADD table_constraint [ NOT VALID ]

This form adds a new constraint to a table using the same constraint syntax as CREATE TABLE, plus the option NOT VALID, which is currently only allowed for foreign key and CHECK constraints. Normally, this form will cause a scan of the table to verify that all existing rows in the table satisfy the new constraint. But if the NOT VALID option is used, this potentially-lengthy scan is skipped. The constraint will still be enforced against subsequent inserts or updates (that is, they'll fail unless there is a matching row in the referenced table, in the case of foreign keys, or they'll fail unless the new row matches the specified check condition). But the database will not assume that the constraint holds for all rows in the table, until it is validated by using the VALIDATE CONSTRAINT option. See Notes below for more information about using the NOT VALID option.

Although most forms of ADD table_constraint require an ACCESS EXCLUSIVE lock, ADD FOREIGN KEY requires only a SHARE ROW EXCLUSIVE lock. Note that ADD FOREIGN KEY also acquires a SHARE ROW EXCLUSIVE lock on the referenced table, in addition to the lock on the table on which the constraint is declared.

Additional restrictions apply when unique or primary key constraints are added to partitioned tables; see CREATE TABLE. Also, foreign key constraints on partitioned tables may not be declared NOT VALID at present.

ADD table_constraint_using_index

This form adds a new PRIMARY KEY or UNIQUE constraint to a table based on an existing unique index. All the columns of the index will be included in the constraint. The index cannot have expression columns nor be a partial index. Also, it must be a b-tree index with default sort ordering. These restrictions ensure that the index is equivalent to one that would be built by a regular ADD PRIMARY KEY or ADD UNIQUE command.

If PRIMARY KEY is specified, and the index's columns are not already marked NOT NULL, then this command will attempt to do ALTER COLUMN SET NOT NULL against each such column. That requires a full table scan to verify the column(s) contain no nulls. In all other cases, this is a fast operation.

If a constraint name is provided then the index will be renamed to match the constraint name. Otherwise the constraint will be named the same as the index.

After this command is executed, the index is “owned” by the constraint, in the same way as if the index had been built by a regular ADD PRIMARY KEY or ADD UNIQUE command. In particular, dropping the constraint will make the index disappear too.

This form is not currently supported on partitioned tables.

Note

Adding a constraint using an existing index can be helpful in situations where a new constraint needs to be added without blocking table updates for a long time. To do that, create the index using CREATE INDEX CONCURRENTLY, and then install it as an official constraint using this syntax. See the example below.

ALTER CONSTRAINT

This form alters the attributes of a constraint that was previously created. Currently only foreign key constraints may be altered.

VALIDATE CONSTRAINT

This form validates a foreign key or check constraint that was previously created as NOT VALID, by scanning the table to ensure there are no rows for which the constraint is not satisfied. Nothing happens if the constraint is already marked valid. (See Notes below for an explanation of the usefulness of this command.) This command acquires a SHARE UPDATE EXCLUSIVE lock.

DROP CONSTRAINT [ IF EXISTS ]

This form drops the specified constraint on a table, along with any index underlying the constraint. If IF EXISTS is specified and the constraint does not exist, no error is thrown. In this case a notice is issued instead.

DISABLE/ENABLE [ REPLICA | ALWAYS ] TRIGGER

These forms configure the firing of trigger(s) belonging to the table. A disabled trigger is still known to the system, but is not executed when its triggering event occurs. For a deferred trigger, the enable status is checked when the event occurs, not when the trigger function is actually executed. One can disable or enable a single trigger specified by name, or all triggers on the table, or only user triggers (this option excludes internally generated constraint triggers such as those that are used to implement foreign key constraints or deferrable uniqueness and exclusion constraints). Disabling or enabling internally generated constraint triggers requires superuser privileges; it should be done with caution since of course the integrity of the constraint cannot be guaranteed if the triggers are not executed. The trigger firing mechanism is also affected by the configuration variable session_replication_role. Simply enabled triggers (the default) will fire when the replication role is “origin” (the default) or “local”. Triggers configured as ENABLE REPLICA will only fire if the session is in “replica” mode, and triggers configured as ENABLE ALWAYS will fire regardless of the current replication role.

The effect of this mechanism is that in the default configuration, triggers do not fire on replicas. This is useful because if a trigger is used on the origin to propagate data between tables, then the replication system will also replicate the propagated data, and the trigger should not fire a second time on the replica, because that would lead to duplication. However, if a trigger is used for another purpose such as creating external alerts, then it might be appropriate to set it to ENABLE ALWAYS so that it is also fired on replicas.

This command acquires a SHARE ROW EXCLUSIVE lock.

DISABLE/ENABLE [ REPLICA | ALWAYS ] RULE

These forms configure the firing of rewrite rules belonging to the table. A disabled rule is still known to the system, but is not applied during query rewriting. The semantics are as for disabled/enabled triggers. This configuration is ignored for ON SELECT rules, which are always applied in order to keep views working even if the current session is in a non-default replication role. The rule firing mechanism is also affected by the configuration variable session_replication_role, analogous to triggers as described above.

DISABLE/ENABLE ROW LEVEL SECURITY

These forms control the application of row security policies belonging to the table. If enabled and no policies exist for the table, then a default-deny policy is applied. Note that policies can exist for a table even if row-level security is disabled. In this case, the policies will not be applied and the policies will be ignored. See also CREATE POLICY.

NO FORCE/FORCE ROW LEVEL SECURITY

These forms control the application of row security policies belonging to the table when the user is the table owner. If enabled, row-level security policies will be applied when the user is the table owner. If disabled (the default) then row-level security will not be applied when the user is the table owner. See also CREATE POLICY.

CLUSTER ON

This form selects the default index for future CLUSTER operations. It does not actually re-cluster the table. Changing cluster options acquires a SHARE UPDATE EXCLUSIVE lock.

SET WITHOUT CLUSTER

This form removes the most recently used CLUSTER index specification from the table. This affects future cluster operations that don't specify an index. Changing cluster options acquires a SHARE UPDATE EXCLUSIVE lock.

SET WITHOUT OIDS

Backward-compatible syntax for removing the oid system column. As oid system columns cannot be added anymore, this never has an effect.

SET TABLESPACE

This form changes the table's tablespace to the specified tablespace and moves the data file(s) associated with the table to the new tablespace. Indexes on the table, if any, are not moved; but they can be moved separately with additional SET TABLESPACE commands. When applied to a partitioned table, nothing is moved, but any partitions created afterwards with CREATE TABLE PARTITION OF will use that tablespace, unless overridden by a TABLESPACE clause. All tables in the current database in a tablespace can be moved by using the ALL IN TABLESPACE form, which will lock all tables to be moved first and then move each one. This form also supports OWNED BY, which will only move tables owned by the roles specified. If the NOWAIT option is specified then the command will fail if it is unable to acquire all of the locks required immediately. Note that system catalogs are not moved by this command; use ALTER DATABASE or explicit ALTER TABLE invocations instead if desired. The information_schema relations are not considered part of the system catalogs and will be moved. See also CREATE TABLESPACE.

SET { LOGGED | UNLOGGED }

This form changes the table from unlogged to logged or vice-versa (see UNLOGGED). It cannot be applied to a temporary table.

SET ( storage_parameter [= value] [, ... ] )

This form changes one or more storage parameters for the table. See Storage Parameters in the CREATE TABLE documentation for details on the available parameters. Note that the table contents will not be modified immediately by this command; depending on the parameter you might need to rewrite the table to get the desired effects. That can be done with VACUUM FULL, CLUSTER or one of the forms of ALTER TABLE that forces a table rewrite. For planner related parameters, changes will take effect from the next time the table is locked so currently executing queries will not be affected. SHARE UPDATE EXCLUSIVE lock will be taken for fillfactor, toast and autovacuum storage parameters, as well as the planner parameter parallel_workers.

RESET ( storage_parameter [, ... ] )

This form resets one or more storage parameters to their defaults. As with SET, a table rewrite might be needed to update the table entirely.

INHERIT parent_table

This form adds the target table as a new child of the specified parent table. Subsequently, queries against the parent will include records of the target table. To be added as a child, the target table must already contain all the same columns as the parent (it could have additional columns, too). The columns must have matching data types, and if they have NOT NULL constraints in the parent then they must also have NOT NULL constraints in the child. There must also be matching child-table constraints for all CHECK constraints of the parent, except those marked non-inheritable (that is, created with ALTER TABLE ... ADD CONSTRAINT ... NO INHERIT) in the parent, which are ignored; all child-table constraints matched must not be marked non-inheritable. Currently UNIQUE, PRIMARY KEY, and FOREIGN KEY constraints are not considered, but this might change in the future.

NO INHERIT parent_table

This form removes the target table from the list of children of the specified parent table. Queries against the parent table will no longer include records drawn from the target table.

OF type_name

This form links the table to a composite type as though CREATE TABLE OF had formed it. The table's list of column names and types must precisely match that of the composite type. The table must not inherit from any other table. These restrictions ensure that CREATE TABLE OF would permit an equivalent table definition.

NOT OF

This form dissociates a typed table from its type.

OWNER TO

This form changes the owner of the table, sequence, view, materialized view, or foreign table to the specified user.

REPLICA IDENTITY

This form changes the information which is written to the write-ahead log to identify rows which are updated or deleted. In most cases, the old value of each column is only logged if it differs from the new value; however, if the old value is stored externally, it is always logged regardless of whether it changed. This option has no effect except when logical replication is in use. DEFAULT

Records the old values of the columns of the primary key, if any. This is the default for non-system tables.

USING INDEX index_name

Records the old values of the columns covered by the named index, that must be unique, not partial, not deferrable, and include only columns marked NOT NULL. If this index is dropped, the behavior is the same as NOTHING.

FULL

Records the old values of all columns in the row.

NOTHING

Records no information about the old row. This is the default for system tables.

RENAME

The RENAME forms change the name of a table (or an index, sequence, view, materialized view, or foreign table), the name of an individual column in a table, or the name of a constraint of the table. When renaming a constraint that has an underlying index, the index is renamed as well. There is no effect on the stored data.

SET SCHEMA

This form moves the table into another schema. Associated indexes, constraints, and sequences owned by table columns are moved as well.

ATTACH PARTITION partition_name { FOR VALUES partition_bound_spec | DEFAULT }

This form attaches an existing table (which might itself be partitioned) as a partition of the target table. The table can be attached as a partition for specific values using FOR VALUES or as a default partition by using DEFAULT. For each index in the target table, a corresponding one will be created in the attached table; or, if an equivalent index already exists, it will be attached to the target table's index, as if ALTER INDEX ATTACH PARTITION had been executed. Note that if the existing table is a foreign table, it is currently not allowed to attach the table as a partition of the target table if there are UNIQUE indexes on the target table. (See also CREATE FOREIGN TABLE (CREATE_FOREIGN_TABLE(7)).) For each user-defined row-level trigger that exists in the target table, a corresponding one is created in the attached table. A partition using FOR VALUES uses same syntax for partition_bound_spec as CREATE TABLE. The partition bound specification must correspond to the partitioning strategy and partition key of the target table. The table to be attached must have all the same columns as the target table and no more; moreover, the column types must also match. Also, it must have all the NOT NULL and CHECK constraints of the target table, not marked NO INHERIT. Currently FOREIGN KEY constraints are not considered. UNIQUE and PRIMARY KEY constraints from the parent table will be created in the partition, if they don't already exist.

If the new partition is a regular table, a full table scan is performed to check that existing rows in the table do not violate the partition constraint. It is possible to avoid this scan by adding a valid CHECK constraint to the table that allows only rows satisfying the desired partition constraint before running this command. The CHECK constraint will be used to determine that the table need not be scanned to validate the partition constraint. This does not work, however, if any of the partition keys is an expression and the partition does not accept NULL values. If attaching a list partition that will not accept NULL values, also add a NOT NULL constraint to the partition key column, unless it's an expression.

If the new partition is a foreign table, nothing is done to verify that all the rows in the foreign table obey the partition constraint. (See the discussion in CREATE FOREIGN TABLE (CREATE_FOREIGN_TABLE(7)) about constraints on the foreign table.)

When a table has a default partition, defining a new partition changes the partition constraint for the default partition. The default partition can't contain any rows that would need to be moved to the new partition, and will be scanned to verify that none are present. This scan, like the scan of the new partition, can be avoided if an appropriate CHECK constraint is present. Also like the scan of the new partition, it is always skipped when the default partition is a foreign table.

Attaching a partition acquires a SHARE UPDATE EXCLUSIVE lock on the parent table, in addition to the ACCESS EXCLUSIVE locks on the table being attached and on the default partition (if any).

Further locks must also be held on all sub-partitions if the table being attached is itself a partitioned table. Likewise if the default partition is itself a partitioned table. The locking of the sub-partitions can be avoided by adding a CHECK constraint as described in Section 5.11.2.2.

DETACH PARTITION partition_name [ CONCURRENTLY | FINALIZE ]

This form detaches the specified partition of the target table. The detached partition continues to exist as a standalone table, but no longer has any ties to the table from which it was detached. Any indexes that were attached to the target table's indexes are detached. Any triggers that were created as clones of those in the target table are removed. SHARE lock is obtained on any tables that reference this partitioned table in foreign key constraints. If CONCURRENTLY is specified, it runs using a reduced lock level to avoid blocking other sessions that might be accessing the partitioned table. In this mode, two transactions are used internally. During the first transaction, a SHARE UPDATE EXCLUSIVE lock is taken on both parent table and partition, and the partition is marked as undergoing detach; at that point, the transaction is committed and all other transactions using the partitioned table are waited for. Once all those transactions have completed, the second transaction acquires SHARE UPDATE EXCLUSIVE on the partitioned table and ACCESS EXCLUSIVE on the partition, and the detach process completes. A CHECK constraint that duplicates the partition constraint is added to the partition. CONCURRENTLY cannot be run in a transaction block and is not allowed if the partitioned table contains a default partition.

If FINALIZE is specified, a previous DETACH CONCURRENTLY invocation that was canceled or interrupted is completed. At most one partition in a partitioned table can be pending detach at a time.

All the forms of ALTER TABLE that act on a single table, except RENAME, SET SCHEMA, ATTACH PARTITION, and DETACH PARTITION can be combined into a list of multiple alterations to be applied together. For example, it is possible to add several columns and/or alter the type of several columns in a single command. This is particularly useful with large tables, since only one pass over the table need be made.

You must own the table to use ALTER TABLE. To change the schema or tablespace of a table, you must also have CREATE privilege on the new schema or tablespace. To add the table as a new child of a parent table, you must own the parent table as well. Also, to attach a table as a new partition of the table, you must own the table being attached. To alter the owner, you must also be a direct or indirect member of the new owning role, and that role must have CREATE privilege on the table's schema. (These restrictions enforce that altering the owner doesn't do anything you couldn't do by dropping and recreating the table. However, a superuser can alter ownership of any table anyway.) To add a column or alter a column type or use the OF clause, you must also have USAGE privilege on the data type.

## PARAMETERS
IF EXISTS

Do not throw an error if the table does not exist. A notice is issued in this case.

name

The name (optionally schema-qualified) of an existing table to alter. If ONLY is specified before the table name, only that table is altered. If ONLY is not specified, the table and all its descendant tables (if any) are altered. Optionally, * can be specified after the table name to explicitly indicate that descendant tables are included.

column_name

Name of a new or existing column.

new_column_name

New name for an existing column.

new_name

New name for the table.

data_type

Data type of the new column, or new data type for an existing column.

table_constraint

New table constraint for the table.

constraint_name

Name of a new or existing constraint.

CASCADE

Automatically drop objects that depend on the dropped column or constraint (for example, views referencing the column), and in turn all objects that depend on those objects (see Section 5.14).

RESTRICT

Refuse to drop the column or constraint if there are any dependent objects. This is the default behavior.

trigger_name

Name of a single trigger to disable or enable.

ALL

Disable or enable all triggers belonging to the table. (This requires superuser privilege if any of the triggers are internally generated constraint triggers such as those that are used to implement foreign key constraints or deferrable uniqueness and exclusion constraints.)

USER

Disable or enable all triggers belonging to the table except for internally generated constraint triggers such as those that are used to implement foreign key constraints or deferrable uniqueness and exclusion constraints.

index_name

The name of an existing index.

storage_parameter

The name of a table storage parameter.

value

The new value for a table storage parameter. This might be a number or a word depending on the parameter.

parent_table

A parent table to associate or de-associate with this table.

new_owner

The user name of the new owner of the table.

new_tablespace

The name of the tablespace to which the table will be moved.

new_schema

The name of the schema to which the table will be moved.

partition_name

The name of the table to attach as a new partition or to detach from this table.

partition_bound_spec

The partition bound specification for a new partition. Refer to CREATE TABLE (CREATE_TABLE(7)) for more details on the syntax of the same.

## NOTES
The key word COLUMN is noise and can be omitted.

When a column is added with ADD COLUMN and a non-volatile DEFAULT is specified, the default is evaluated at the time of the statement and the result stored in the table's metadata. That value will be used for the column for all existing rows. If no DEFAULT is specified, NULL is used. In neither case is a rewrite of the table required.

Adding a column with a volatile DEFAULT or changing the type of an existing column will require the entire table and its indexes to be rewritten. As an exception, when changing the type of an existing column, if the USING clause does not change the column contents and the old type is either binary coercible to the new type or an unconstrained domain over the new type, a table rewrite is not needed; but any indexes on the affected columns must still be rebuilt. Table and/or index rebuilds may take a significant amount of time for a large table; and will temporarily require as much as double the disk space.

Adding a CHECK or NOT NULL constraint requires scanning the table to verify that existing rows meet the constraint, but does not require a table rewrite.

Similarly, when attaching a new partition it may be scanned to verify that existing rows meet the partition constraint.

The main reason for providing the option to specify multiple changes in a single ALTER TABLE is that multiple table scans or rewrites can thereby be combined into a single pass over the table.

Scanning a large table to verify a new foreign key or check constraint can take a long time, and other updates to the table are locked out until the ALTER TABLE ADD CONSTRAINT command is committed. The main purpose of the NOT VALID constraint option is to reduce the impact of adding a constraint on concurrent updates. With NOT VALID, the ADD CONSTRAINT command does not scan the table and can be committed immediately. After that, a VALIDATE CONSTRAINT command can be issued to verify that existing rows satisfy the constraint. The validation step does not need to lock out concurrent updates, since it knows that other transactions will be enforcing the constraint for rows that they insert or update; only pre-existing rows need to be checked. Hence, validation acquires only a SHARE UPDATE EXCLUSIVE lock on the table being altered. (If the constraint is a foreign key then a ROW SHARE lock is also required on the table referenced by the constraint.) In addition to improving concurrency, it can be useful to use NOT VALID and VALIDATE CONSTRAINT in cases where the table is known to contain pre-existing violations. Once the constraint is in place, no new violations can be inserted, and the existing problems can be corrected at leisure until VALIDATE CONSTRAINT finally succeeds.

The DROP COLUMN form does not physically remove the column, but simply makes it invisible to SQL operations. Subsequent insert and update operations in the table will store a null value for the column. Thus, dropping a column is quick but it will not immediately reduce the on-disk size of your table, as the space occupied by the dropped column is not reclaimed. The space will be reclaimed over time as existing rows are updated.

To force immediate reclamation of space occupied by a dropped column, you can execute one of the forms of ALTER TABLE that performs a rewrite of the whole table. This results in reconstructing each row with the dropped column replaced by a null value.

The rewriting forms of ALTER TABLE are not MVCC-safe. After a table rewrite, the table will appear empty to concurrent transactions, if they are using a snapshot taken before the rewrite occurred. See Section 13.5 for more details.

The USING option of SET DATA TYPE can actually specify any expression involving the old values of the row; that is, it can refer to other columns as well as the one being converted. This allows very general conversions to be done with the SET DATA TYPE syntax. Because of this flexibility, the USING expression is not applied to the column's default value (if any); the result might not be a constant expression as required for a default. This means that when there is no implicit or assignment cast from old to new type, SET DATA TYPE might fail to convert the default even though a USING clause is supplied. In such cases, drop the default with DROP DEFAULT, perform the ALTER TYPE, and then use SET DEFAULT to add a suitable new default. Similar considerations apply to indexes and constraints involving the column.

If a table has any descendant tables, it is not permitted to add, rename, or change the type of a column in the parent table without doing the same to the descendants. This ensures that the descendants always have columns matching the parent. Similarly, a CHECK constraint cannot be renamed in the parent without also renaming it in all descendants, so that CHECK constraints also match between the parent and its descendants. (That restriction does not apply to index-based constraints, however.) Also, because selecting from the parent also selects from its descendants, a constraint on the parent cannot be marked valid unless it is also marked valid for those descendants. In all of these cases, ALTER TABLE ONLY will be rejected.

A recursive DROP COLUMN operation will remove a descendant table's column only if the descendant does not inherit that column from any other parents and never had an independent definition of the column. A nonrecursive DROP COLUMN (i.e., ALTER TABLE ONLY ... DROP COLUMN) never removes any descendant columns, but instead marks them as independently defined rather than inherited. A nonrecursive DROP COLUMN command will fail for a partitioned table, because all partitions of a table must have the same columns as the partitioning root.

The actions for identity columns (ADD GENERATED, SET etc., DROP IDENTITY), as well as the actions TRIGGER, CLUSTER, OWNER, and TABLESPACE never recurse to descendant tables; that is, they always act as though ONLY were specified. Adding a constraint recurses only for CHECK constraints that are not marked NO INHERIT.

Changing any part of a system catalog table is not permitted.

Refer to CREATE TABLE (CREATE_TABLE(7)) for a further description of valid parameters. Chapter 5 has further information on inheritance.

## EXAMPLES
To add a column of type varchar to a table:

```
ALTER TABLE distributors ADD COLUMN address varchar(30);
```

That will cause all existing rows in the table to be filled with null values for the new column.

To add a column with a non-null default:

```
ALTER TABLE measurements

  ADD COLUMN mtime timestamp with time zone DEFAULT now();
```

Existing rows will be filled with the current time as the value of the new column, and then new rows will receive the time of their insertion.

To add a column and fill it with a value different from the default to be used later:

```
ALTER TABLE transactions

  ADD COLUMN status varchar(30) DEFAULT 'old',

  ALTER COLUMN status SET default 'current';
```

Existing rows will be filled with old, but then the default for subsequent commands will be current. The effects are the same as if the two sub-commands had been issued in separate ALTER TABLE commands.

To drop a column from a table:

```
ALTER TABLE distributors DROP COLUMN address RESTRICT;
```

To change the types of two existing columns in one operation:

```
ALTER TABLE distributors

    ALTER COLUMN address TYPE varchar(80),

    ALTER COLUMN name TYPE varchar(100);
```

To change an integer column containing Unix timestamps to timestamp with time zone via a USING clause:

```
ALTER TABLE foo

    ALTER COLUMN foo_timestamp SET DATA TYPE timestamp with time zone

    USING

        timestamp with time zone 'epoch' + foo_timestamp * interval '1 second';
```

The same, when the column has a default expression that won't automatically cast to the new data type:

```
ALTER TABLE foo

    ALTER COLUMN foo_timestamp DROP DEFAULT,

    ALTER COLUMN foo_timestamp TYPE timestamp with time zone

    USING

        timestamp with time zone 'epoch' + foo_timestamp * interval '1 second',

    ALTER COLUMN foo_timestamp SET DEFAULT now();
```

To rename an existing column:

```
ALTER TABLE distributors RENAME COLUMN address TO city;
```

To rename an existing table:

```
ALTER TABLE distributors RENAME TO suppliers;
```

To rename an existing constraint:

```
ALTER TABLE distributors RENAME CONSTRAINT zipchk TO zip_check;
```

To add a not-null constraint to a column:

```
ALTER TABLE distributors ALTER COLUMN street SET NOT NULL;
```

To remove a not-null constraint from a column:

```
ALTER TABLE distributors ALTER COLUMN street DROP NOT NULL;
```

To add a check constraint to a table and all its children:

```
ALTER TABLE distributors ADD CONSTRAINT zipchk CHECK (char_length(zipcode) = 5);
```

To add a check constraint only to a table and not to its children:

```
ALTER TABLE distributors ADD CONSTRAINT zipchk CHECK (char_length(zipcode) = 5) NO INHERIT;
```

(The check constraint will not be inherited by future children, either.)

To remove a check constraint from a table and all its children:

```
ALTER TABLE distributors DROP CONSTRAINT zipchk;
```

To remove a check constraint from one table only:

```
ALTER TABLE ONLY distributors DROP CONSTRAINT zipchk;
```

(The check constraint remains in place for any child tables.)

To add a foreign key constraint to a table:

```
ALTER TABLE distributors ADD CONSTRAINT distfk FOREIGN KEY (address) REFERENCES addresses (address);
```

To add a foreign key constraint to a table with the least impact on other work:

```
ALTER TABLE distributors ADD CONSTRAINT distfk FOREIGN KEY (address) REFERENCES addresses (address) NOT VALID;
ALTER TABLE distributors VALIDATE CONSTRAINT distfk;
```

To add a (multicolumn) unique constraint to a table:

```
ALTER TABLE distributors ADD CONSTRAINT dist_id_zipcode_key UNIQUE (dist_id, zipcode);
```

To add an automatically named primary key constraint to a table, noting that a table can only ever have one primary key:

```
ALTER TABLE distributors ADD PRIMARY KEY (dist_id);
```

To move a table to a different tablespace:

```
ALTER TABLE distributors SET TABLESPACE fasttablespace;
```

To move a table to a different schema:

```
ALTER TABLE myschema.distributors SET SCHEMA yourschema;
```

To recreate a primary key constraint, without blocking updates while the index is rebuilt:

```
CREATE UNIQUE INDEX CONCURRENTLY dist_id_temp_idx ON distributors (dist_id);
ALTER TABLE distributors DROP CONSTRAINT distributors_pkey,

    ADD CONSTRAINT distributors_pkey PRIMARY KEY USING INDEX dist_id_temp_idx;
```

To attach a partition to a range-partitioned table:

```
ALTER TABLE measurement

    ATTACH PARTITION measurement_y2016m07 FOR VALUES FROM ('2016-07-01') TO ('2016-08-01');
```

To attach a partition to a list-partitioned table:

```
ALTER TABLE cities

    ATTACH PARTITION cities_ab FOR VALUES IN ('a', 'b');
```

To attach a partition to a hash-partitioned table:

```
ALTER TABLE orders

    ATTACH PARTITION orders_p4 FOR VALUES WITH (MODULUS 4, REMAINDER 3);
```

To attach a default partition to a partitioned table:

```
ALTER TABLE cities

    ATTACH PARTITION cities_partdef DEFAULT;
```

To detach a partition from a partitioned table:

```
ALTER TABLE measurement

    DETACH PARTITION measurement_y2015m12;
```

## COMPATIBILITY
The forms ADD (without USING INDEX), DROP [COLUMN], DROP IDENTITY, RESTART, SET DEFAULT, SET DATA TYPE (without USING), SET GENERATED, and SET sequence_option conform with the SQL standard. The other forms are PostgreSQL extensions of the SQL standard. Also, the ability to specify more than one manipulation in a single ALTER TABLE command is an extension.

ALTER TABLE DROP COLUMN can be used to drop the only column of a table, leaving a zero-column table. This is an extension of SQL, which disallows zero-column tables.

## SEE ALSO
CREATE TABLE (CREATE_TABLE(7))


title: ALTER_TABLESPACE(7)

summary: change the definition of a tablespace

text:
# ALTER_TABLESPACE(7)

## NAME
ALTER_TABLESPACE - change the definition of a tablespace

## SYNOPSIS

```
ALTER TABLESPACE name RENAME TO new_name
ALTER TABLESPACE name OWNER TO { new_owner | CURRENT_ROLE | CURRENT_USER | SESSION_USER }
ALTER TABLESPACE name SET ( tablespace_option = value [, ... ] )
ALTER TABLESPACE name RESET ( tablespace_option [, ... ] )
```

## DESCRIPTION
ALTER TABLESPACE can be used to change the definition of a tablespace.

You must own the tablespace to change the definition of a tablespace. To alter the owner, you must also be a direct or indirect member of the new owning role. (Note that superusers have these privileges automatically.)

## PARAMETERS
name

The name of an existing tablespace.

new_name

The new name of the tablespace. The new name cannot begin with pg_, as such names are reserved for system tablespaces.

new_owner

The new owner of the tablespace.

tablespace_option

A tablespace parameter to be set or reset. Currently, the only available parameters are seq_page_cost, random_page_cost, effective_io_concurrency and maintenance_io_concurrency. Setting these values for a particular tablespace will override the planner's usual estimate of the cost of reading pages from tables in that tablespace, and the executor's prefetching behavior, as established by the configuration parameters of the same name (see seq_page_cost, random_page_cost, effective_io_concurrency, maintenance_io_concurrency). This may be useful if one tablespace is located on a disk which is faster or slower than the remainder of the I/O subsystem.

## EXAMPLES
Rename tablespace index_space to fast_raid:

```
ALTER TABLESPACE index_space RENAME TO fast_raid;
```

Change the owner of tablespace index_space:

```
ALTER TABLESPACE index_space OWNER TO mary;
```

## COMPATIBILITY
There is no ALTER TABLESPACE statement in the SQL standard.

## SEE ALSO
CREATE TABLESPACE (CREATE_TABLESPACE(7)), DROP TABLESPACE (DROP_TABLESPACE(7))


title: ALTER_TEXT_SEARCH_CONFIGURATION(7)

text:
# ALTER_TEXT_SEARCH_CONFIGURATION(7)

## NAME
ALTER_TEXT_SEARCH_CONFIGURATION - change the definition of a text search configuration

## SYNOPSIS

```
ALTER TEXT SEARCH CONFIGURATION name

    ADD MAPPING FOR token_type [, ... ] WITH dictionary_name [, ... ]
ALTER TEXT SEARCH CONFIGURATION name

    ALTER MAPPING FOR token_type [, ... ] WITH dictionary_name [, ... ]
ALTER TEXT SEARCH CONFIGURATION name

    ALTER MAPPING REPLACE old_dictionary WITH new_dictionary
ALTER TEXT SEARCH CONFIGURATION name

    ALTER MAPPING FOR token_type [, ... ] REPLACE old_dictionary WITH new_dictionary
ALTER TEXT SEARCH CONFIGURATION name

    DROP MAPPING [ IF EXISTS ] FOR token_type [, ... ]
ALTER TEXT SEARCH CONFIGURATION name RENAME TO new_name
ALTER TEXT SEARCH CONFIGURATION name OWNER TO { new_owner | CURRENT_ROLE | CURRENT_USER | SESSION_USER }
ALTER TEXT SEARCH CONFIGURATION name SET SCHEMA new_schema
```

## DESCRIPTION
ALTER TEXT SEARCH CONFIGURATION changes the definition of a text search configuration. You can modify its mappings from token types to dictionaries, or change the configuration's name or owner.

You must be the owner of the configuration to use ALTER TEXT SEARCH CONFIGURATION.

## PARAMETERS
name

The name (optionally schema-qualified) of an existing text search configuration.

token_type

The name of a token type that is emitted by the configuration's parser.

dictionary_name

The name of a text search dictionary to be consulted for the specified token type(s). If multiple dictionaries are listed, they are consulted in the specified order.

old_dictionary

The name of a text search dictionary to be replaced in the mapping.

new_dictionary

The name of a text search dictionary to be substituted for old_dictionary.

new_name

The new name of the text search configuration.

new_owner

The new owner of the text search configuration.

new_schema

The new schema for the text search configuration.

The ADD MAPPING FOR form installs a list of dictionaries to be consulted for the specified token type(s); it is an error if there is already a mapping for any of the token types. The ALTER MAPPING FOR form does the same, but first removing any existing mapping for those token types. The ALTER MAPPING REPLACE forms substitute new_dictionary for old_dictionary anywhere the latter appears. This is done for only the specified token types when FOR appears, or for all mappings of the configuration when it doesn't. The DROP MAPPING form removes all dictionaries for the specified token type(s), causing tokens of those types to be ignored by the text search configuration. It is an error if there is no mapping for the token types, unless IF EXISTS appears.

## EXAMPLES
The following example replaces the english dictionary with the swedish dictionary anywhere that english is used within my_config.

```
ALTER TEXT SEARCH CONFIGURATION my_config

  ALTER MAPPING REPLACE english WITH swedish;
```

## COMPATIBILITY
There is no ALTER TEXT SEARCH CONFIGURATION statement in the SQL standard.

## SEE ALSO
CREATE TEXT SEARCH CONFIGURATION (CREATE_TEXT_SEARCH_CONFIGURATION(7)), DROP TEXT SEARCH CONFIGURATION (DROP_TEXT_SEARCH_CONFIGURATION(7))