对于那些试图评估他们需要哪一个Heroku计划，又不能等待Heroku的慢行计数器刷新的人来说，一个简单实用的答案是:

基本上你想在psql中运行\dt，将结果复制到你最喜欢的文本编辑器中(它看起来像这样:

 public | auth_group                     | table | axrsosvelhutvw
 public | auth_group_permissions         | table | axrsosvelhutvw
 public | auth_permission                | table | axrsosvelhutvw
 public | auth_user                      | table | axrsosvelhutvw
 public | auth_user_groups               | table | axrsosvelhutvw
 public | auth_user_user_permissions     | table | axrsosvelhutvw
 public | background_task                | table | axrsosvelhutvw
 public | django_admin_log               | table | axrsosvelhutvw
 public | django_content_type            | table | axrsosvelhutvw
 public | django_migrations              | table | axrsosvelhutvw
 public | django_session                 | table | axrsosvelhutvw
 public | exercises_assignment           | table | axrsosvelhutvw

)，然后运行regex搜索并替换，如下所示:

^[^|]*\|\s+([^|]*?)\s+\| table \|.*$

to:

select '\1', count(*) from \1 union/g

这将会给你一个非常类似的结果:

select 'auth_group', count(*) from auth_group union
select 'auth_group_permissions', count(*) from auth_group_permissions union
select 'auth_permission', count(*) from auth_permission union
select 'auth_user', count(*) from auth_user union
select 'auth_user_groups', count(*) from auth_user_groups union
select 'auth_user_user_permissions', count(*) from auth_user_user_permissions union
select 'background_task', count(*) from background_task union
select 'django_admin_log', count(*) from django_admin_log union
select 'django_content_type', count(*) from django_content_type union
select 'django_migrations', count(*) from django_migrations union
select 'django_session', count(*) from django_session
;

(您需要删除最后一个联合，并手动在末尾添加分号)

在psql中运行它，就完成了。

            ?column?            | count
--------------------------------+-------
 auth_group_permissions         |     0
 auth_user_user_permissions     |     0
 django_session                 |  1306
 django_content_type            |    17
 auth_user_groups               |   162
 django_admin_log               |  9106
 django_migrations              |    19
[..]

如果您在psql shell中，使用\gexec允许您执行syed的答案和Aur的答案中描述的语法，而无需在外部文本编辑器中手动编辑。

with x (y) as (
    select
        'select count(*), '''||
        tablename||
        ''' as "tablename" from '||
        tablename||' '
    from pg_tables
    where schemaname='public'
)
select
    string_agg(y,' union all '||chr(10)) || ' order by tablename'
from x \gexec

注意，string_agg()既用于分隔所有语句之间的联合，也用于将分隔的数据箭头粉碎为一个单元，以便传递到缓冲区。

\ gexec 将当前查询缓冲区发送到服务器，然后将查询输出的每一行的每一列(如果有的话)视为要执行的SQL语句。

简单的两步:(注意:不需要改变任何东西-只是复制粘贴) 1. 创建函数

create function 
cnt_rows(schema text, tablename text) returns integer
as
$body$
declare
  result integer;
  query varchar;
begin
  query := 'SELECT count(1) FROM ' || schema || '.' || tablename;
  execute query into result;
  return result;
end;
$body$
language plpgsql;

2. 运行此查询获取所有表的行数

select sum(cnt_rows) as total_no_of_rows from (select 
  cnt_rows(table_schema, table_name)
from information_schema.tables
where 
  table_schema not in ('pg_catalog', 'information_schema') 
  and table_type='BASE TABLE') as subq;

或 按表获取行数

select
  table_schema,
  table_name, 
  cnt_rows(table_schema, table_name)
from information_schema.tables
where 
  table_schema not in ('pg_catalog', 'information_schema') 
  and table_type='BASE TABLE'
order by 3 desc;

下面是一个解决方案，它不需要函数来获得每个表的精确计数:

select table_schema, 
       table_name, 
       (xpath('/row/cnt/text()', xml_count))[1]::text::int as row_count
from (
  select table_name, table_schema, 
         query_to_xml(format('select count(*) as cnt from %I.%I', table_schema, table_name), false, true, '') as xml_count
  from information_schema.tables
  where table_schema = 'public' --<< change here for the schema you want
) t

query_to_xml将运行传递的SQL查询并返回带有结果的XML(该表的行数)。外层xpath()将从该xml中提取计数信息并将其转换为数字

实际上并不需要派生表，但可以使xpath()更容易理解——否则整个query_to_xml()将需要传递给xpath()函数。

这对我很有效

SELECT schemaname,relname,n_live_tup FROM pg_stat_user_tables ORDER BY n_live_tup DESC;

要获得估计，请参阅格雷格·史密斯的答案。

为了得到确切的数字，到目前为止，其他答案都受到一些问题的困扰，其中一些问题很严重(见下文)。这里有一个版本，希望更好:

CREATE FUNCTION rowcount_all(schema_name text default 'public')
  RETURNS table(table_name text, cnt bigint) as
$$
declare
 table_name text;
begin
  for table_name in SELECT c.relname FROM pg_class c
    JOIN pg_namespace s ON (c.relnamespace=s.oid)
    WHERE c.relkind = 'r' AND s.nspname=schema_name
  LOOP
    RETURN QUERY EXECUTE format('select cast(%L as text),count(*) from %I.%I',
       table_name, schema_name, table_name);
  END LOOP;
end
$$ language plpgsql;

它接受模式名作为参数，如果没有给出参数，则接受public。

要使用特定的模式列表或来自查询的列表而不修改函数，可以从查询中调用它，如下所示:

WITH rc(schema_name,tbl) AS (
  select s.n,rowcount_all(s.n) from (values ('schema1'),('schema2')) as s(n)
)
SELECT schema_name,(tbl).* FROM rc;

这将生成一个包含模式、表和行计数的3列输出。

下面是这个函数避免的其他答案中的一些问题:

Table and schema names shouldn't be injected into executable SQL without being quoted, either with quote_ident or with the more modern format() function with its %I format string. Otherwise some malicious person may name their table tablename;DROP TABLE other_table which is perfectly valid as a table name. Even without the SQL injection and funny characters problems, table name may exist in variants differing by case. If a table is named ABCD and another one abcd, the SELECT count(*) FROM... must use a quoted name otherwise it will skip ABCD and count abcd twice. The %I of format does this automatically. information_schema.tables lists custom composite types in addition to tables, even when table_type is 'BASE TABLE' (!). As a consequence, we can't iterate oninformation_schema.tables, otherwise we risk having select count(*) from name_of_composite_type and that would fail. OTOH pg_class where relkind='r' should always work fine. The type of COUNT() is bigint, not int. Tables with more than 2.15 billion rows may exist (running a count(*) on them is a bad idea, though). A permanent type need not to be created for a function to return a resultset with several columns. RETURNS TABLE(definition...) is a better alternative.