1.查询表大小：

postgres=# \dList of relationsSchema |       Name        | Type  | Owner  |       Storage
--------+-------------------+-------+--------+----------------------public | compress_column_t | table | hgimdb | append only columnarpublic | hgimdbtab         | table | hgimdb | heappublic | hgimdbtab_ext     | table | hgimdb | externalpublic | hgimdbtab_load_t  | table | hgimdb | heappublic | trips_column      | table | hgimdb | append only columnar
(5 rows)postgres=# select pg_size_pretty(pg_relation_size('hgimdbtab_load_t'));pg_size_pretty
----------------32 GB
(1 row)postgres=#

2.查询模式大小：

postgres=# select schemaname ,round(sum(pg_total_relation_size(schemaname||'.'||tablename))/1024/1024) "Size_MB"                                                                     from pg_tables where schemaname='public' group by 1;schemaname | Size_MB
------------+---------public     |   33906
(1 row)

3.查询数据库大小：

postgres=# select pg_size_pretty(pg_database_size('postgres'));pg_size_pretty
----------------33 GB
(1 row)

4.查询所有数据库大小：

postgres=# \lList of databasesName    | Owner  | Encoding | Access privileges
-----------+--------+----------+-------------------postgres  | hgimdb | UTF8     |template0 | hgimdb | UTF8     | =c/hgimdb: hgimdb=CTc/hgimdbtemplate1 | hgimdb | UTF8     | =c/hgimdb: hgimdb=CTc/hgimdbtest      | hgimdb | UTF8     |tpch      | hgimdb | UTF8     |
(5 rows)postgres=# select datname,pg_size_pretty(pg_database_size(datname)) from pg_database;datname  | pg_size_pretty
-----------+----------------template1 | 94 MBtemplate0 | 93 MBpostgres  | 33 GBtpch      | 93 MBtest      | 93 MB
(5 rows)postgres=# select sodddatname, (sodddatsize/1073741824) AS sizeinGB from gp_toolkit.gp_size_of_database;sodddatname | sizeingb
-------------+----------tpch        |        0test        |        0
(2 rows)postgres=#

5.查询分区表的总大小（包括索引和分区）：

postgres=# select schemaname,tablename,round(sum(pg_total_relation_size(schemaname || '.' || partitiontablename))/1024/1024) "MB"                                                    from pg_partitions where tablename='compress_column_t' group by 1,2;schemaname | tablename | MB
------------+-----------+----
(0 rows)