Re: pg_toast growth out - PostgreSQL 9.2

["David G. Johnston" <david.g.johnston@xxxxxxxxx>]

On Wed, Mar 16, 2016 at 3:47 PM, drum.lucas@xxxxxxxxx <drum.lucas@xxxxxxxxx> wrote:

Hi all,

Trying to understand how can the pg_toast table be 90% of my entire DB?

It isn't "the", its "one of my".  "One of my pg_toast" tables consumes 90% of my entire DB".  Though its remotely possible you only have one it is not generally the case.

 

SELECT nspname || '.' || relname AS "relation",
    pg_size_pretty(pg_relation_size(C.oid)) AS "size"
  FROM pg_class C
  LEFT JOIN pg_namespace N ON (N.oid = C.relnamespace)
  WHERE nspname NOT IN ('pg_catalog', 'information_schema')
  ORDER BY pg_relation_size(C.oid) DESC
  LIMIT 20;

Results:

pg_toast.pg_toast_7255249   1581 GB
public.ja_feedlog   81 GB

Total DB size: 1.7 TB

What's going on here?

​http://www.postgresql.org/docs/current/static/storage-toast.html​

 

Is there anything I can do to save up some disk space?

Not outside of radical changes to your architecture or deleting records - though possibly marginal improvements could be made dependent upon the type of data that is being "toasted".

David J.