简单方便的获取所有表的条数

文档用途

我们知道oracle里有一个系统表存的rownum。本文旨在介绍在HG数据库中简单方便的获取所有表的条数的方法。

详细信息

通过如下sql：

selectrelnameas表名,reltuplesas条数frompg_classwhererelkind='r'andrelnamespace=(selectoidfrompg_namespacewherenspname='highgo')orderby条数desc;

效果如下：

highgo=# select relname as 表名, reltuples as 条数 from pg_class where relkind = 'r' and relnamespace = (select oid from pg_namespace where nspname='highgo') order by 条数 desc;表名|条数-------------+--------t1|0aaa|0b|0test1|0t|0d1|0d2|0product|0addressbook|5(9rows)

在很多情况下这个值是一个参考值，想更新此值可以通过如下命令：

highgo=# select * from t1;a|b---+---3|a(1row)highgo=# analyze t1;ANALYZE

效果如下：

highgo=# select relname as 表名, reltuples as 条数 from pg_class where relkind = 'r' and relnamespace = (select oid from pg_namespace where nspname='highgo') order by 条数 desc;表名|条数-------------+--------t1|1aaa|0b|0test1|0t|0d1|0d2|0product|0addressbook|5(9rows)