ALTER OPERATOR FAMILY

ALTER OPERATOR FAMILY

7

SQL - Language Statements

ALTER OPERATOR FAMILY

change the definition of an operator family

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
[???](#sql-createopclass).) 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 [???](#xindex) 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
========
