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 .)
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 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