1. PG里如何查看表，索引，表空间，数据库大小
--查询一个索引大小 select pg_size_pretty(pg_relation_size('indexname))--查看一张表及此它上的索引总大小 select pg_size_pretty(pg_total_relation_size('tablename')); --查看所有 schema里面索引大小，大到小的顺序排列： select indexrelname,pg_size_pretty( pg_relation_size(relid)) from pg_stat_user_indexes where schemaname = 'schemaname' order by pg_relation_size(relid) desc;--查看所有 schema里面表的大小，从大到小顺序排列： select relname, pg_size_pretty(pg_relation_size(relid)) from pg_stat_user_tables where schemaname = 'schemaname' order by pg_relation_size(relid) desc; --查看数据库大小： select pg_database.datname,pg_size_pretty(pg_database_size(pg_database.datname)) AS size from pg_database;--查看表空间大小