查看数据库硬盘占用量相关命令总结

一.连接数据库

/opt/pg93/bin/psql -h Host -p port -d database -U user

二.查看数据库的大小

my_db=# select pg_size_pretty(pg_database_size('log_analysis'));
 pg_size_pretty 
----------------
 1100 GB
(1 row)

三.按照表的大小降序排列

log_analysis=# select schemaname,relname,pg_size_pretty(pg_relation_size(relid)) 
log_analysis-# from pg_stat_user_tables
log_analysis-# order by pg_relation_size(relid) desc;
    schemaname     |                         relname                          | pg_size_pretty 
-------------------+----------------------------------------------------------+----------------
 dw                | sp_product_view_history                                  | 109 GB
 dw                | sp_sight_view_history                                    | 42 GB
 public            | touch_ticket_channel_201504                              | 41 GB
 history           | stat_sight_user_area_touch                               | 30 GB
 public            | touch_ticket_channel_201502                              | 30 GB
 history           | stat_sight_user_area_www                                 | 30 GB
 public            | touch_ticket_channel_201503                              | 25 GB
 dw                | product_online                                           | 25 GB
 public            | touch_ticket_channel_201501                              | 19 GB
 public            | ticket_channel_data                                      | 15 GB

四.查询某个表的行数

log_analysis=# SELECT reltuples 
log_analysis-#   FROM pg_class r JOIN pg_namespace p  on r.relnamespace = p.oid 
log_analysis-#  WHERE relkind = 'r'  and nspname='public' AND relname = 'touch_ticket_channel_201503';
  reltuples  
-------------
 2.60146e+07
(1 row)