Question
How can I list all the tables of a PostgreSQL database and order them by size?
Solution
https://stackoverflow.com/questions/21738408
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Russianselect table_name, pg_relation_size(quote_ident(table_name))
from information_schema.tables
where table_schema = 'public'
order by 2
This shows you the size of all tables in the schema public if you have multiple schemas, you might want to use:
select table_schema, table_name, pg_relation_size('"'||table_schema||'"."'||table_name||'"')
from information_schema.tables
order by 3
SQLFiddle example: http://sqlfiddle.com/#!15/13157/3
List of all object size functions in the manual.
OTHER TIPS
This will show you the schema name, table name, size pretty and size (needed for sort).
SELECT
schema_name,
relname,
pg_size_pretty(table_size) AS size,
table_size
FROM (
SELECT
pg_catalog.pg_namespace.nspname AS schema_name,
relname,
pg_relation_size(pg_catalog.pg_class.oid) AS table_size
FROM pg_catalog.pg_class
JOIN pg_catalog.pg_namespace ON relnamespace = pg_catalog.pg_namespace.oid
) t
WHERE schema_name NOT LIKE 'pg_%'
ORDER BY table_size DESC;
I build this based on the solutions from here list of schema with sizes (relative and absolute) in a PostgreSQL database
This will be more clear.
pg_size_pretty(<numeric_value>) - converts no.of bytes to human-readable format.
pg_database_size(<db_name>) - gets database size in bytes.
pg_total_relation_size(<relation_name>) - gets total size of table and its index in bytes.
pg_relation_size(<relation_name>) - gets relation (table/index) size in bytes.
pg_indexes_size(<relation_name>) - gets index size of the relation in bytes.
current_database() - gets the currently used database on which this query is being performed.
Query:
select current_database() as database,
pg_size_pretty(total_database_size) as total_database_size,
schema_name,
table_name,
pg_size_pretty(total_table_size) as total_table_size,
pg_size_pretty(table_size) as table_size,
pg_size_pretty(index_size) as index_size
from ( select table_name,
table_schema as schema_name,
pg_database_size(current_database()) as total_database_size,
pg_total_relation_size(table_name) as total_table_size,
pg_relation_size(table_name) as table_size,
pg_indexes_size(table_name) as index_size
from information_schema.tables
where table_schema=current_schema() and table_name like 'table_%'
order by total_table_size
) as sizes;
Result:
database | total_database_size | schema_name | table_name | total_table_size | table_size | index_size
-----------+---------------------+-------------+------------+------------------+------------+------------
vigneshdb | 1586 MB | corpdata | table_aaa | 16 kB | 0 bytes | 8192 bytes
vigneshdb | 1586 MB | corpdata | table_bbb | 24 kB | 0 bytes | 16 kB
vigneshdb | 1586 MB | corpdata | table_ccc | 640 kB | 112 kB | 488 kB
vigneshdb | 1586 MB | corpdata | table_ddd | 9760 kB | 3152 kB | 6568 kB
vigneshdb | 1586 MB | corpdata | table_eee | 1120 MB | 311 MB | 808 MB
The humanized format is represent in bytes, kB, MB, GB, and TB.
bytes to kB - begins from 10240 bytes
bytes to MB - begins from 10485248 bytes = 10239.5 kB ~ 10 MB
bytes to GB - begins from 10736893952 bytes = 10239.5 MB ~ 10 BG
bytes to TB - begins from 10994579406848 bytes = 10239.5 GB ~ 10 TB
All unit conversions starts from 10 + <unit>.
For reference - Postgres Official Documentation
I like following statement:
SELECT
table_name,
pg_size_pretty( pg_total_relation_size(quote_ident(table_name))),
pg_total_relation_size(quote_ident(table_name))
FROM
information_schema.tables
WHERE
table_schema = 'public'
ORDER BY
pg_total_relation_size(quote_ident(table_name)) DESC
You can see total size in a pretty format, but it is ordered correctly too.
SELECT
relname as "Table",
pg_size_pretty(pg_total_relation_size(relid)) As "Size",
pg_size_pretty(pg_total_relation_size(relid) - pg_relation_size(relid)) as "External Size"
FROM pg_catalog.pg_statio_user_tables ORDER BY pg_total_relation_size(relid) DESC;
taken from here https://wiki-bsse.ethz.ch/display/ITDOC/Check+size+of+tables+and+objects+in+PostgreSQL+database
I needed to find which tables use the most space.
Based on other answers, I used that query:
select table_name, pg_size_pretty( pg_relation_size(quote_ident(table_name)) )
from information_schema.tables
where table_schema = 'public'
order by pg_relation_size(quote_ident(table_name)) desc
I get the following result:
table_name pg_size_pretty
--------------------------------------
trade_binance 96 GB
closs_v2_binance_stash 46 GB
closs_bitfinex_stash 5725 MB
trade_bitfinex 5112 MB
...
api_requests 0 bytes
trade_huobi 0 bytes
I should have bought a bigger SSD.
SELECT nspname || '.' || relname AS "relation",
pg_size_pretty(pg_total_relation_size(C.oid)) AS "total_size"
FROM pg_class C
LEFT JOIN pg_namespace N ON (N.oid = C.relnamespace)
WHERE nspname NOT IN ('pg_catalog', 'information_schema')
AND C.relkind <> 'i'
AND nspname !~ '^pg_toast'
ORDER BY pg_total_relation_size(C.oid) DESC
;
Credit: https://makandracards.com/makandra/52141-postgresql-how-to-show-table-sizes
select table_name,n_live_tup, pg_size_pretty(pg_relation_size(table_name))
from information_schema.tables
inner join pg_stat_user_tables on table_name=relname
where table_schema = 'public'
order by 2 desc
Another alternative
If you're looking for a breakdown in total, toast and index sizes use this:
SELECT *, pg_size_pretty(total_bytes) AS total
, pg_size_pretty(index_bytes) AS INDEX
, pg_size_pretty(toast_bytes) AS toast
, pg_size_pretty(table_bytes) AS TABLE
FROM (
SELECT *, total_bytes-index_bytes-COALESCE(toast_bytes,0) AS table_bytes
FROM (
SELECT c.oid,nspname AS table_schema, relname AS TABLE_NAME
, c.reltuples AS row_estimate
, pg_total_relation_size(c.oid) AS total_bytes
, pg_indexes_size(c.oid) AS index_bytes
, pg_total_relation_size(reltoastrelid) AS toast_bytes
FROM pg_class c
LEFT JOIN pg_namespace n ON n.oid = c.relnamespace
WHERE relkind = 'r'
) a
) a ORDER BY total_bytes DESC;
select table_name, pg_size_pretty(pg_total_relation_size(quote_ident(table_name)))
from information_schema.tables
where table_schema = 'public'
order by pg_total_relation_size(quote_ident(table_name));
pg_total_relation_size would include size of indexes as well as tables.
If you want only the table size, then pg_relation_size would be enough.
select uv.a tablename, pg_size_pretty(uv.b) sizepretty
from (select tb.tablename a, pg_table_size('schemaname.'||tb.tablename::text) b
from pg_tables tb
where tb.schemaname ilike 'schemaname'
order by 2 desc
) uv
You can get total relation size and relation size, which may be different depending on your tables relationships. Now here's how to get top 100 tables on your database:
SELECT schemaname AS table_schema,
relname AS table_name,
PG_SIZE_PRETTY(PG_TOTAL_RELATION_SIZE(relid)) AS total_size,
PG_SIZE_PRETTY(PG_RELATION_SIZE(relid)) AS data_size,
PG_SIZE_PRETTY(PG_TOTAL_RELATION_SIZE(relid) - PG_RELATION_SIZE(relid))
AS external_size
FROM pg_catalog.pg_statio_user_tables
ORDER BY PG_TOTAL_RELATION_SIZE(relid) DESC,
PG_RELATION_SIZE(relid) DESC
LIMIT 100;
Most of the answers here use pg_size_pretty which is very useful, but if you want to the output as a numerical value you can calculate this yourself like
SELECT tab_size /1024 AS size_kb
,tab_size /1024 /1024 AS size_mb
,tab_size /1024 /1024 / 1024 AS size_gb
,tab_size /1024 /1024 / 1024 / 1024 AS size_tb
FROM
(
SELECT pg_total_relation_size(relid) AS tab_size
FROM pg_catalog.pg_statio_user_tables
WHERE schemaname = 'your_schema'
AND relname = 'your_table'
) AS tabs;
