| ALTER_OPERATOR_FAMILY(7) - phpMan
ALTER OPERATOR FAMILY(7) PostgreSQL 12.3 Documentation 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_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 37.16 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
left-unary or right-unary 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 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. A 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))
PostgreSQL 12.3 2020 ALTER OPERATOR FAMILY(7)
|