mirror of
https://github.com/postgres/postgres.git
synced 2025-10-29 22:49:41 +03:00
116 lines
3.7 KiB
Plaintext
116 lines
3.7 KiB
Plaintext
This module contains several functions that report the on-disk size of a
|
|
given database object in bytes:
|
|
|
|
int8 database_size(name)
|
|
int8 relation_size(text)
|
|
int8 indexes_size(text)
|
|
int8 total_relation_size(text)
|
|
|
|
int8 pg_database_size(oid)
|
|
int8 pg_relation_size(oid)
|
|
int8 pg_tablespace_size(oid)
|
|
|
|
text pg_size_pretty(int8)
|
|
|
|
setof record relation_size_components(text)
|
|
|
|
The first four functions take the name of the object (possibly
|
|
schema-qualified for the latter three) and returns the size of the
|
|
on-disk files in bytes.
|
|
|
|
SELECT database_size('template1');
|
|
SELECT relation_size('pg_class');
|
|
SELECT indexes_size('pg_class');
|
|
SELECT total_relation_size('pg_class');
|
|
|
|
These functions take object OIDs:
|
|
|
|
SELECT pg_database_size(1); -- template1 database
|
|
SELECT pg_relation_size(1259); -- pg_class table size
|
|
SELECT pg_tablespace_size(1663); -- pg_default tablespace
|
|
|
|
The indexes_size() function returns the total size of the indices for a
|
|
relation, including any toasted indices.
|
|
|
|
The total_relation_size() function returns the total size of the relation,
|
|
all its indices, and any toasted data.
|
|
|
|
Please note that relation_size and pg_relation_size report only the size of
|
|
the selected relation itself; any related indexes or toast tables are not
|
|
counted. To obtain the total size of a table including all indices and
|
|
toasted data, use total_relation_size().
|
|
|
|
The last function, relation_size_components(), returns a set of rows
|
|
showing the sizes of the component relations constituting the input
|
|
relation.
|
|
|
|
Examples
|
|
========
|
|
|
|
I've loaded the following table with a little less than 3 MB of data for
|
|
illustration:
|
|
|
|
create table fat ( id serial, data varchar );
|
|
create index fat_uidx on fat (id);
|
|
create index fat_idx on fat (data);
|
|
|
|
You can retrieve a rowset containing constituent sizes as follows:
|
|
|
|
# SELECT relation_size_components('fat');
|
|
relation_size_components
|
|
----------------------------------------------------
|
|
(2088960,65536,2891776,fat,r,59383,59383)
|
|
(32768,704512,737280,pg_toast_59383,t,59386,59386)
|
|
(0,32768,32768,pg_toast_59383_index,i,59388,59388)
|
|
(0,2039808,2039808,fat_idx,i,59389,59389)
|
|
(0,49152,49152,fat_uidx,i,59911,59911)
|
|
(5 rows)
|
|
|
|
To see a more readable output of the rowset:
|
|
|
|
SELECT *
|
|
FROM relation_size_components('fat') AS (idxsize BIGINT,
|
|
datasize BIGINT,
|
|
totalsize BIGINT,
|
|
relname NAME,
|
|
kind "char",
|
|
relid OID,
|
|
node OID)
|
|
ORDER BY totalsize;
|
|
|
|
idxsize | datasize | totalsize | relname | kind | relid | node
|
|
---------+----------+-----------+----------------------+------+-------+-------
|
|
0 | 32768 | 32768 | pg_toast_59383_index | i | 59388 | 59388
|
|
0 | 49152 | 49152 | fat_uidx | i | 59911 | 59911
|
|
32768 | 704512 | 737280 | pg_toast_59383 | t | 59386 | 59386
|
|
0 | 2039808 | 2039808 | fat_idx | i | 59389 | 59389
|
|
2088960 | 65536 | 2891776 | fat | r | 59383 | 59383
|
|
(5 rows)
|
|
|
|
To see the sum total size of a relation:
|
|
|
|
# select total_relation_size('fat');
|
|
total_relation_size
|
|
-------------------------
|
|
2891776
|
|
(1 row)
|
|
|
|
To see just the size of the uncompressed relation data:
|
|
|
|
# select relation_size('fat');
|
|
relation_size
|
|
---------------
|
|
65536
|
|
(1 row)
|
|
|
|
To see the size of all related indices:
|
|
|
|
# select indexes_size('fat');
|
|
indexes_size
|
|
--------------
|
|
2088960
|
|
(1 row)
|
|
|
|
To install, just run make; make install. Then load the functions
|
|
into any database using dbsize.sql.
|