Thread: PostgreSQL 9.5.14 Documentation /Chapter 28 / 28.1. Determining DiskUsage
PostgreSQL 9.5.14 Documentation /Chapter 28 / 28.1. Determining DiskUsage
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The following documentation comment has been logged on the website: Page: https://www.postgresql.org/docs/9.5/static/disk-usage.html Description: PostgreSQL 9.5.14 Documentation / Chapter 28. Monitoring Disk Usage / 28.1. Determining Disk Usage (Applies for other Versions, too.) I'm wondering if the two statements given showing the index space size as described. I've the impression they show the space size of the tables. Regards --Michael Extract of the manual: You can easily display index sizes, too: SELECT c2.relname, c2.relpages FROM pg_class c, pg_class c2, pg_index i WHERE c.relname = 'customer' AND c.oid = i.indrelid AND c2.oid = i.indexrelid ORDER BY c2.relname; relname | relpages ----------------------+---------- customer_id_indexdex | 26 It is easy to find your largest tables and indexes using this information: SELECT relname, relpages FROM pg_class ORDER BY relpages DESC; relname | relpages ----------------------+---------- bigtable | 3290
Re: PostgreSQL 9.5.14 Documentation /Chapter 28 / 28.1. DeterminingDisk Usage
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"David G. Johnston"
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I'm wondering if the two statements given showing the index space size as
described.
I've the impression they show the space size of the tables.
"Each page is typically 8 kilobytes. (Remember, relpages is only updated by VACUUM, ANALYZE, and a few DDL commands such as CREATE INDEX.)"
So while it takes a bit of interpretation it is stated that "relpages" are not a size on their own but a value to be multiplied by 8k to come up with the disk size (typically since one can compile the server with a different page size).
David J.