ROUTE_TO 提示

ROUTE_TO 提示将查询路由到指定的卷标识或服务类型。

语法

代码语法 ::= 'indexserver' | 'xsengine' | 'scriptserver' | 'dpserver' | 'computeserver' ::= ROUTE_TO( [{, }] ) | ROUTE_TO( '' [{, '' }] ) | NO_ROUTE_TO( [{, }] ) | NO_ROUTE_TO( '' [{, '' }] ) | ROUTE_BY( [{, }] ) | ROUTE_BY_CARDINALITY( [{, }] ) | DATA_TRANSFER_COST ({0 | 1})

描述

ROUTE_TO 提示可以与“卷标识”或“服务类型”一起使用。如果提供“卷标识”，则语句将路由到指定卷。但是，如果在提示中提供“服务类型”（可以具有如 "indexserver"、"computeserver" 等值的字符串参数），则可以将语句路由到与此服务相关的所有节点。

示例

示例代码create table mytab(a int);insert into mytab values(1); select * from mytab with hint(ROUTE_TO('indexserver'));select * from mytab with hint(ROUTE_TO('indexserver','computeserver')); select * from mytab with hint(NO_ROUTE_TO('indexserver'));select * from mytab with hint(NO_ROUTE_TO('indexserver','computeserver')); select preferred_routing_volumes, * from sys.m_sql_plan_cache_ where statement_string like '%select * from mytab%';