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From: Gary Stainburn <gary.stainburn@ringways.co.uk>
To: pgsql-sql@postgresql.org
Subject: left outer join with count
Date: Fri, 29 May 2020 17:09:16 +0100
Message-ID: <202005291709.16647.gary.stainburn@ringways.co.uk> (raw)

I have the following select:

select sj.*, sr.*, wd.doc_count from
  service_jobs sj
  left outer join service_receptions sr on sr.sr_id = sj.sj_sr_id
  left outer join (select sj_id, count(sj_id) as doc_count from work_documents wd group by sj_id) wd on wd.wd_sj_id = sj.sj_id;

While the select works, I can't help thinking that the last join is expensive.  Is there a cleaner (quicker) method of doing this?

Gary

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