CREATE [ OR REPLACE ] [ TEMP | TEMPORARY ] [ RECURSIVE ] VIEW name [ ( column_name [, ...] ) ] [ WITH ( view_option_name [= view_option_value] [, ... ] ) ] AS query [ WITH [ CASCADED | LOCAL ] CHECK OPTION ] warehouse_db=# \h create materialized view Command: CREATE ...
CREATE MATERIALIZED VIEW [IF NOT EXISTS] table_name [(column_name[,...])] [WITH (storage_parameter [=value][,...])] [TABLESPACE tablespace_name] AS query [WITH [NO] DATA] 创建物化视图 CREATE MATERIALIZED VIEW student_view_m AS SELECT * FROM student LEFT JOIN teacher ON student.teache...
PostgreSQL materialized views example We’ll use the tables in the sample database for creating a materialized view. First, create a materialized view named rental_by_category using the CREATE MATERIALIZED VIEW statement: CREATE MATERIALIZED VIEW rental_by_category AS SELECT c.name AS category, sum...
PostgreSQL物化视图(materialized view) 1、创建视图 1 2 3 4 5 6 CREATE MATERIALIZED VIEW [ IF NOT EXISTS ] table_name [ (column_name [, ...] ) ] [ WITH ( storage_parameter [= value] [, ... ] ) ] [ TABLESPACE tablespace_name ] AS query [ WITH [ NO ] DATA ] 2、删除视图 1...
CREATE MATERIALIZED VIEW类似于 CREATE TABLE AS,不过它还会记住被用来初始化该视图的查询, 这样它可以在后来被命令刷新。 一个物化视图有很多和表相同的属性,但是不支持临时物化视图以及自动生成 OID。 ALTER MATERIALIZED VIEW 更改一个物化视图的定义 ALTER MATERIALIZED VIEW [ IF EXISTS ] name ...
但是必须有索引且刷新速度会变慢(用时间换取查询锁)。目前还不支持增量查询。 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. PostgreSQL物化视图(materialized view) - 郭雪原 - 用一个例子来演示会更加清晰
一个有用的物化视图示例是，用于为销售员创建控制面板显示图表。通过计划任务，每天运行特定SQL语句更新该统计信息。创建一个新的物化视图，即通过`CREATE MATERIALIZED VIEW`命令定义，该命令执行查询填充视图，除非使用`WITH NO DATA`选项。之后，可以使用`REFRESH MATERIALIZED VIEW`命令刷新视图内容。物化...
CREATE MATERIALIZED VIEW IF NOT EXISTS mv_t1_t2 (t1_id,t2_id, col1,col2,col3,col4,col5) AS SELECT , , t1.col1,t1.col2,t2.col3,t2.col4,t2.col5 from t1,t2 where = WITH DATA; mytest=# select * from mv_t1_t2;
postgresql materialized view原理 PostgreSQL的物化视图(Materialized View)是一种预先计算的视图,它将视图的结果保存在数据库中,以便后续查询时可以直接使用。与普通视图不同,物化视图在创建后会立即计算出结果并将其保存在磁盘上,这样可以提高查询性能。 物化视图的原理如下: 1.创建物化视图:使用CREATE MATERIALIZED VIEW...
test=# create materialized view v2 as SELECT a, b, c*4 from base; SELECT 3 test=# select * from v2 where a > 6; a | b | ?column? ---+---+--- 7 | 8 | 36 (1 row) The keyword MATERIALIZED is added to the view definition. In the above example, the materialized view...