创建一个视图 CREATEORREPLACEVIEWstudent_view ASSELECT*FROMstudentLEFTJOINteacherONstudent.teacher_id=teacher.id; 创建一个物化视图 CREATEMATERIALIZEDVIEWstudent_view_m ASSELECT*FROMstudentLEFTJOINteacherONstudent.teacher_id=teacher.id; student_view去每个表中进行查询,而student_view_m 直接去视图表查询,而...
创建一个视图 CREATEORREPLACEVIEWstudent_viewASSELECT*FROMstudentLEFTJOINteacherONstudent.teacher_id=teacher.id; 创建一个物化视图 CREATEMATERIALIZEDVIEWstudent_view_mASSELECT*FROMstudentLEFTJOINteacherONstudent.teacher_id=teacher.id; 进行查询explain: master=>explainselect*fromstudent_view; QUERY PLAN---Hash...
postgres=# CREATE OR REPLACE FUNCTION tri_foo_func() RETURNS TRIGGER AS $$ BEGIN REFRESH MATERIALIZED VIEW mvfoo; RETURN NULL; END; $$ LANGUAGE plpgsql; 由于我们将要创建的是一个AFTER触发器, 所以函数返回NULL即可 创建AFTER触发器自身 CREATE TRIGGER tri_foo AFTER INSERT OR UPDATE OR DELETE ON f...
CREATE OR REPLACE VIEW student_view AS SELECT * FROM student LEFT JOIN teacher ON student.teacher_id = teacher.id; 1. 2. 3. 4. 5. 创建一个物化视图 AI检测代码解析 CREATE MATERIALIZED VIEW student_view_m AS SELECT * FROM student LEFT JOIN teacher ON student.teacher_id = teacher.id; 1...
CREATE MATERIALIZED VIEW — Define a new materialized view. Synopsis → WrapCopy CREATE MATERIALIZED VIEW <name> [<build_clause>][<create_mv_refresh>] AS subquery Where <build_clause> is: BUILD {IMMEDIATE | DEFERRED} Where <create_mv_refresh> is: REFRESH [COMPLETE] [...
postgres 提示materialized view不存在 post-materialism 超材料是一种人工材料,其性能取决于特定的结构设计而非化学成分。超材料通过特殊的结构设计能够实现常规材料不具有的属性。不同于自然界中的材料,构成物质的基本单元是原子或分子。超材料的基本单元是具有特殊几何结构设计的单元。超材料能够产生自然材料不具有的等效...
createorreplacefunctiontri_tableName_mview_func()returnstriggeras$$declarebeginrefresh materializedviewconcurrently tableName_mviewwithdata;returnnull;end; $$languageplpgsql;createtriggertri_tableName_idu afterinsertorupdateordeleteontableNameforeachstatementexecuteproceduretri_tableName_mview_func(); ...
The unique index ensures that each row in the materialized view can be uniquely identified. The b-tree index we added earlier has not been explicitly declared as unique, so we can add a new unique index and drop the old one. CREATE UNIQUE INDEX unique_idx_recent_product_sales ON recent_...
...其他修改原视图字段的操作,只能删除视图重新创建) postgres=# create or replace view emp_details_view postgres-# as select postgres...| postgres (1 row) 删除视图 postgres=# drop view emp_view2; DROP VIEW 可更新视图 如果一个视图满足以下条件,它就是自动可更新的: 在该视图的...PostgreSQL ...
CREATE VIEW Name CREATE VIEW-- define a new view. Synopsis → WrapCopy CREATE [ OR REPLACE ] VIEW <name> [ ( <column_name> [, ...] ) ] AS <query> Description CREATE VIEWdefines a view of a query. The view is not physically materialized. Instead, the query is run every time ...