NAME

DROP OPERATOR CLASS - 刪除一個操作符類

SYNOPSIS

DROP OPERATOR CLASS name USING index_method [ CASCADE | RESTRICT ]

DESCRIPTION 描述

DROP OPERATOR CLASS 從數(shù)據(jù)庫中刪除一個現(xiàn)有操作符表。要執(zhí)行這條命令，你必須是此操作符表的所有者。  

PARAMETERS 參數(shù)

name

 一個現(xiàn)存操作符表的名字（可以用模式修飾）。

index_method

 操作符表所對付的索引訪問方法的名字。

CASCADE

 自動刪除依賴于該操作符表的對象。

RESTRICT

 如果有任何依賴對象存在，則拒絕刪除此操作符表。這個行為是缺省。

EXAMPLES 例子

 刪除 B-tree 操作符表 widget_ops：

DROP OPERATOR CLASS widget_ops USING btree;

 如果有任何現(xiàn)存的索引使用這個操作符表，那么這條命令將不能 執(zhí)行。增加一個 CASCADE 刪除這樣的索引以及這個 操作符表。  

COMPATIBILITY 兼容性

 在 SQL 標(biāo)準(zhǔn)里沒有 DROP OPERATOR CLASS。  

SEE ALSO 參見

ALTER OPERATOR CLASS [alter_operator_class(7)], CREATE OPERATOR CLASS [create_operator_class(l)]

#p#

NAME

DROP OPERATOR CLASS - remove an operator class

SYNOPSIS

DROP OPERATOR CLASS 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.  

PARAMETERS

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.

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(l)]