获取 Postgres 数据库中每个表的行数

Question

What is the most efficient way to get a row count of all tables in my database?

I'm using a Postgres database.

Example Result

table_name     row_count
------------   -------------
some_table     1,234
foobar         5,678
another_table  32
... 

Answer 1

if you want a perticular table's rowcount then it will work

SELECT reltuples FROM pg_class WHERE oid = 'my_schema.my_table'::regclass;

reltuples is a column from pg_class table, it holds data about "number of rows >in the table. This is only an estimate used by the planner.

and if your want a list of all tables with its rowcount then it will do the job

SELECT
  pgClass.relname   AS tableName,
  pgClass.reltuples AS rowCount
FROM
  pg_class pgClass
INNER JOIN
  pg_namespace pgNamespace ON (pgNamespace.oid = pgClass.relnamespace)
WHERE
  pgNamespace.nspname NOT IN ('pg_catalog', 'information_schema') AND
  pgClass.relkind='r'

"Why is "SELECT count(*) FROM bigtable;" slow?" : count(*)

Answer 2

For total row count of entire database use this

SELECT
  SUM(pgClass.reltuples) AS totalRowCount
FROM
  pg_class pgClass
LEFT JOIN
  pg_namespace pgNamespace ON (pgNamespace.oid = pgClass.relnamespace)
WHERE
  pgNamespace.nspname NOT IN ('pg_catalog', 'information_schema') AND
  pgClass.relkind='r'

And the row counts for the specific tables in the same database go for this

SELECT
  pgClass.relname   AS tableName,
  pgClass.reltuples AS rowCount
FROM
  pg_class pgClass
LEFT JOIN
  pg_namespace pgNamespace ON (pgNamespace.oid = pgClass.relnamespace)
WHERE
  pgNamespace.nspname NOT IN ('pg_catalog', 'information_schema') AND
  pgClass.relkind='r'

For reference here is thelink