postgres=# CREATE MATERIALIZED VIEW mvfoo AS SELECT * FROM foo; 创建刷新物化视图的触发器函数 postgres=# CREATE OR REPLACE FUNCTION tri_foo_func() RETURNS TRIGGER AS $$ BEGIN REFRESH MATERIALIZED VIEW mvfoo; RETURN NULL
warehouse_db=# create materialized view mat_view as select * from warehouse_tb1 with no data; SELECT 0 warehouse_db=# select * from mat_view ; ERROR: materialized view "mat_view" has not been populated HINT: Use the REFRESH MATERIALIZED VIEW command. warehouse_db=# refresh materialized vie...
ON DEMAND 指示伺服器通過調用 DBMS_MVIEW 包或調用 Postgres REFRESH MATERIALIZED VIEW 語句來按需重新整理具體化檢視。這是預設行為。 樣本 以下語句建立名為 dept_30 的具體化檢視: CREATE MATERIALIZED VIEW dept_30 BUILD IMMEDIATE AS SELECT * FROM emp WHERE deptno = 30; 該視圖包含從 emp 表中檢索的、...
To load data into a materialized view, you use the REFRESH MATERIALIZED VIEW statement: REFRESH MATERIALIZED VIEW view_name; When you refresh data for a materialized view, PostgreSQL locks the underlying tables. Consequently, you will not be able to retrieve data from underlying tables while data...
For more information about the PostgresREFRESH MATERIALIZED VIEWcommand, see thePostgreSQL core documentation. Examples This statement creates a materialized view nameddept_30: CREATEMATERIALIZEDVIEWdept_30 BUILD IMMEDIATEASSELECT*FROMempWHEREdeptno=30; ...
REFRESH MATERIALIZED VIEW country_total_debt_2; Querying a Materialized View By now, you should have two materialized views (country_total_debt, country_total_debt_2) created. Let's execute a simple select query using any of the two - ...
子句包含关键字refresh, 且关键字后带有complete和/或on demand。其中: complete 用于命令服务器丢弃当前内容, 且在刷新物化视图时,通过执行视图的定义查询来重载物化视图。 ON demand 用于命令服务器根据要求来刷新物化视图,这时需要调用包dbms_mview或调用Postgres refresh materialized view语句。这是一种缺省行为。
Once you run REFRESH MATERIALIZED VIEW, we’ll end up with the new data in our materialized view, like so:The thing is, REFRESHing a view can be expensive, and to understand why we should understand a bit more about how they work and why they get out of date....
包括create_mv_refresh 子句以指定应何时更新具体化视图的内容。子句包含 REFRESH 关键字,后跟 COMPLETE 和/或 ON DEMAND,其中: COMPLETE 指示服务器放弃当前内容,并在刷新具体化视图时,通过执行视图的定义查询来重新加载具体化视图。 ON DEMAND 指示服务器通过调用 DBMS_MVIEW 包或调用 Postgres REFRESH MATERIALIZED...
MATERIALIZED VIEW CREATE MATERIALIZED VIEW会创建一个全量物化视图,并且后续可以使用REFRESH MATERIALIZED VIEW(全量刷新)刷新物化视图的数据。 CREATE MATERIALIZED VIEW类似于CREATE TABLE 来自:帮助中心 查看更多 → REFRESH MATERIALIZED VIEW REFRESH MATERIALIZED VIEW 功能描述 REFRESH MATERIALIZED VIEW会以全量刷新...