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dbsize.c | ||
dbsize.sql.in | ||
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README.dbsize |
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.