建议对报表类的或生成基础数据的查询,使用物化视图 (MATERIALIZED VIEW) 定期固化数据快照,避免对多表(尤其是读写频繁的表)重复跑相同的查询,且物化视图支持 REFRESH MATERIALIZED VIEW CONCURRENTLY,支持并发更新如有一个程序需要不断查询 tdsql_pg_main 的总记录数,可参考如下操作。 postg
建议对报表类的或生成基础数据的查询,使用物化视图(MATERIALIZEDVIEW)定期固化数据快照,避免对多表(尤其多写频繁的表)重复跑相同的查询,且物化视图支持REFRESH MATERIALIZED VIEW CONCURRENTLY, 支持并发更新; 如有一个程序需要不断查询TBase_main的总记录数,那么我们这样做: postgres=# select count(1) from tbase_mai...
涉及修改和锁定数据的语句:update,delete,select for update 例外命令:以下语句可以在查询部分用到并行 CREATE TABLE ... AS,SELECT INTO,CREATE MATERIALIZED VIEW,REFRESH MATERIALIZED VIEW 可以被暂停的语句 用DECLARE CURSOR创建的游标 FOR x IN query LOOP .. END LOOP形式的 PL/pgSQL 循环 定义了parallel uns...
13、避免频繁count大表,实时性要求不高的场景,可以定期count,并将count结果缓存使用 14、建议对报表类的或生成基础数据的查询,使用物化视图(MATERIALIZED VIEW)定期固化数据 快照,避免对多表(尤其多写频繁的表)重复跑相同的查询。PostgreSQL中物化视图支持并发更 新:REFRESH MATERIALIZED VIEW CONCURRENTLY。原理和优缺点...
no parallel plans for that query will be generated. As an exception, the following commands, which create a new table and populate it, can use a parallel plan for the underlying SELECT part of the query: CREATE TABLE … AS\SELECT INTO\CREATE MATERIALIZED VIEW\REFRESH MATERIALIZED VIEW. 查询...
6.PostgreSQL 9.4：REFRESH MATERIALIZED VIEW 新增 CONCURRENTLY 参数 7.PostgreSQL 9.4：新增 ALTER ...
Materialized views are also supported and the data in materialized views can be updated using the REFRESH MATERIALIZED VIEW statement. SQL Server SQL Server views can be used to restrict user access to data for security purposes. Both user-defined and system-defined views are supported. ...
PostgreSQL的功能非常强大,但是要把PostgreSQL用好,开发人员是非常关键的。 下面将针对PostgreSQL数据库原理与特性,输出一份开发规范,希望可以减少大家在使用PostgreSQL数据库过程中遇到的困惑。 目标是将PostgreSQL的功能、性能发挥好,她好我也好。 PostgreSQL 使用规范 ...
MAPPING MATCH MATERIALIZED MAXVALUE METHOD MINUTE_P MINVALUE MODE MONTH_P MOVE NAME_P NAMES NATIONAL NATURAL NCHAR NEW NEXT NO NONE NOT NOTHING NOTIFY NOTNULL NOWAIT NULL_P NULLIF NULLS_P NUMERIC OBJECT_P OF OFF OFFSET OIDS OLD ON ONLY OPERATOR OPTION OPTIONS OR ...
Create a Materialized View: CREATE MATERIALIZED VIEW top_customers AS SELECT customer_id, SUM(amount) AS total_spent FROM sales GROUP BY customer_id ORDER BY total_spent DESC; Refresh the View Periodically: REFRESH MATERIALIZED VIEW top_customers; ...