DROP OPERATOR CLASS(7) PostgreSQL 9.2.7 Documentation DROP OPERATOR CLASS(7)NAME
DROP_OPERATOR_CLASS - remove an operator class
SYNOPSIS
DROP OPERATOR CLASS [ IF EXISTS ] name USING index_method [ CASCADE | RESTRICT ]
DESCRIPTION
DROP OPERATOR CLASS drops an existing operator class. To execute this command you must be the owner of the operator class.
DROP OPERATOR CLASS does not drop any of the operators or functions referenced by the class. If there are any indexes depending on the
operator class, you will need to specify CASCADE for the drop to complete.
PARAMETERS
IF EXISTS
Do not throw an error if the operator class does not exist. A notice is issued in this case.
name
The name (optionally schema-qualified) of an existing operator class.
index_method
The name of the index access method the operator class is for.
CASCADE
Automatically drop objects that depend on the operator class.
RESTRICT
Refuse to drop the operator class if any objects depend on it. This is the default.
NOTES
DROP OPERATOR CLASS will not drop the operator family containing the class, even if there is nothing else left in the family (in
particular, in the case where the family was implicitly created by CREATE OPERATOR CLASS). An empty operator family is harmless, but for
the sake of tidiness you might wish to remove the family with DROP OPERATOR FAMILY; or perhaps better, use DROP OPERATOR FAMILY in the
first place.
EXAMPLES
Remove the B-tree operator class widget_ops:
DROP OPERATOR CLASS widget_ops USING btree;
This command will not succeed if there are any existing indexes that use the operator class. Add CASCADE to drop such indexes along with
the operator class.
COMPATIBILITY
There is no DROP OPERATOR CLASS statement in the SQL standard.
SEE ALSO
ALTER OPERATOR CLASS (ALTER_OPERATOR_CLASS(7)), CREATE OPERATOR CLASS (CREATE_OPERATOR_CLASS(7)), DROP OPERATOR FAMILY
(DROP_OPERATOR_FAMILY(7))
PostgreSQL 9.2.7 2014-02-17 DROP OPERATOR CLASS(7)
Check Out this Related Man Page
CREATE OPERATOR CLASS(7) SQL Commands CREATE OPERATOR CLASS(7)NAME
CREATE OPERATOR CLASS - define a new operator class for indexes
SYNOPSIS
CREATE OPERATOR CLASS name [ DEFAULT ] FOR TYPE data_type USING access_method AS
{ OPERATOR strategy_number operator_id [ ( type, type ) ] [ RECHECK ]
| FUNCTION support_number func_name ( parameter_types )
| STORAGE storage_type
} [, ... ]
INPUTS
name The name of the operator class to be created. The name may be schema-qualified.
DEFAULT
If present, the operator class will become the default index operator class for its data type. At most one operator class can be the
default for a specific data type and access method.
data_type
The column data type that this operator class is for.
access_method
The name of the index access method this operator class is for.
strategy_number
The index access method's strategy number for an operator associated with the operator class.
operator_id
The identifier (optionally schema-qualified) of an operator associated with the operator class.
type The input data type(s) of an operator, or NONE to signify a left-unary or right-unary operator. The input data types may be omitted
in the normal case where they are the same as the operator class's data type.
RECHECK
If present, the index is ``lossy'' for this operator, and so the tuples retrieved using the index must be rechecked to verify that
they actually satisfy the qualification clause involving this operator.
support_number
The index access method's support procedure number for a function associated with the operator class.
func_name
The name (optionally schema-qualified) of a function that is an index access method support procedure for the operator class.
parameter_types
The parameter data type(s) of the function.
storage_type
The data type actually stored in the index. Normally this is the same as the column data type, but some index access methods (only
GIST at this writing) allow it to be different. The STORAGE clause must be omitted unless the index access method allows a different
type to be used.
OUTPUTS
CREATE OPERATOR CLASS
Message returned if the operator class is successfully created.
DESCRIPTION
CREATE OPERATOR CLASS defines a new operator class, name.
An operator class defines how a particular data type can be used with an index. The operator class specifies that certain operators will
fill particular roles or ``strategies'' for this data type and this access method. The operator class also specifies the support procedures
to be used by the index access method when the operator class is selected for an index column. All the operators and functions used by an
operator class must be defined before the operator class is created.
If a schema name is given then the operator class is created in the specified schema. Otherwise it is created in the current schema (the
one at the front of the search path; see CURRENT_SCHEMA()). Two operator classes in the same schema can have the same name only if they
are for different index access methods.
The user who defines an operator class becomes its owner. Presently, the creating user must be a superuser. (This restriction is made
because an erroneous operator class definition could confuse or even crash the server.)
CREATE OPERATOR CLASS does not presently check whether the class definition includes all the operators and functions required by the index
access method. It is the user's responsibility to define a valid operator class.
Refer to the chapter on interfacing extensions to indexes in the PostgreSQL Programmer's Guide for further information.
NOTES
Refer to DROP OPERATOR CLASS [drop_operator_class(7)] to delete user-defined operator classes from a database.
USAGE
The following example command defines a GiST index operator class for data type _int4 (array of int4). See contrib/intarray/ for the com-
plete example.
CREATE OPERATOR CLASS gist__int_ops
DEFAULT FOR TYPE _int4 USING gist AS
OPERATOR 3 &&,
OPERATOR 6 = RECHECK,
OPERATOR 7 @,
OPERATOR 8 ~,
OPERATOR 20 @@ (_int4, query_int),
FUNCTION 1 g_int_consistent (internal, _int4, int4),
FUNCTION 2 g_int_union (bytea, internal),
FUNCTION 3 g_int_compress (internal),
FUNCTION 4 g_int_decompress (internal),
FUNCTION 5 g_int_penalty (internal, internal, internal),
FUNCTION 6 g_int_picksplit (internal, internal),
FUNCTION 7 g_int_same (_int4, _int4, internal);
The OPERATOR, FUNCTION, and STORAGE clauses may appear in any order.
COMPATIBILITY
SQL92
CREATE OPERATOR CLASS is a PostgreSQL extension. There is no CREATE OPERATOR CLASS statement in SQL92.
SQL - Language Statements 2002-11-22 CREATE OPERATOR CLASS(7)