DROP TRANSFORM
DROP TRANSFORM — удалить трансформацию
Синтаксис
DROP TRANSFORM [ IF EXISTS ] FORимя_типа
LANGUAGEимя_языка
Описание
DROP TRANSFORM
удаляет ранее определённую трансформацию.
Чтобы удалить трансформацию, необходимо быть владельцем типа и языка. Такие же требования действуют и при создании трансформации.
Параметры
IF EXISTS
Не считать ошибкой, если трансформация не существует. В этом случае будет выдано замечание.
имя_типа
Имя типа данных, для которого предназначена трансформация.
имя_языка
Имя языка, для которого предназначена трансформация.
CASCADE
Автоматически удалять объекты, зависящие от данной трансформации.
RESTRICT
Отказать в удалении трансформации, если от неё зависят какие-либо объекты. Это поведение по умолчанию.
Примеры
Удаление трансформации для типа hstore
и языка plpythonu
:
DROP TRANSFORM FOR hstore LANGUAGE plpythonu;
Совместимость
Эта форма DROP TRANSFORM
является расширением PostgreSQL. За подробностями обратитесь к описанию CREATE TRANSFORM.
См. также
CREATE TRANSFORMCREATE OPERATOR FAMILY
CREATE OPERATOR FAMILY — define a new operator family
Synopsis
CREATE OPERATOR FAMILYname
USINGindex_method
Description
CREATE OPERATOR FAMILY
creates a new operator family. An operator family defines a collection of related operator classes, and perhaps some additional operators and support functions that are compatible with these operator classes but not essential for the functioning of any individual index. (Operators and functions that are essential to indexes should be grouped within the relevant operator class, rather than being “loose” in the operator family. Typically, single-data-type operators are bound to operator classes, while cross-data-type operators can be loose in an operator family containing operator classes for both data types.)
The new operator family is initially empty. It should be populated by issuing subsequent CREATE OPERATOR CLASS
commands to add contained operator classes, and optionally ALTER OPERATOR FAMILY
commands to add “loose” operators and their corresponding support functions.
If a schema name is given then the operator family is created in the specified schema. Otherwise it is created in the current schema. Two operator families in the same schema can have the same name only if they are for different index methods.
The user who defines an operator family becomes its owner. Presently, the creating user must be a superuser. (This restriction is made because an erroneous operator family definition could confuse or even crash the server.)
Refer to Section 36.16 for further information.
Parameters
name
The name of the operator family to be created. The name can be schema-qualified.
index_method
The name of the index method this operator family is for.
Compatibility
CREATE OPERATOR FAMILY
is a Postgres Pro extension. There is no CREATE OPERATOR FAMILY
statement in the SQL standard.