Date: Tue, 16 Jun 2020 17:05:26 -0500
From: Justin Pryzby <pryzby@telsasoft.com>
To: Nagaraj Raj <nagaraj.sf@yahoo.com>
Cc: pgsql-performance@lists.postgresql.org
Subject: Re: simple query running for ever
Message-ID: <20200616220526.GK20404@telsasoft.com>
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On Tue, Jun 16, 2020 at 08:35:31PM +0000, Nagaraj Raj wrote:
> I wrote a simple query, and it is taking too long, not sure what is wrong in it, even its not giving EXPLAIN ANALYZE.
> 
> select T0."physical_address_sid", T0."individual_entity_proxy_id", T2."infrrd_hh_rank_nbr"
> from "cms_prospects".PROSPECT T0
> --inner join "sas_prs_tmp".DEDUPE3583E3F18 T1 on T0."individual_entity_proxy_id" = T1."individual_entity_proxy_id"
> left join "cms_prospects".INDIVIDUAL_DEMOGRAPHIC T2 on T0."individual_entity_proxy_id" = T2."individual_entity_proxy_id" 

Pardon me for saying so, but this query seems silly.

It's self-joining a table on its PK, which I don't think could ever be useful.

You do maybe more than 2x as much work, to get 2x as many columns, which are
all redundant.

Can't you just change 
T2."infrrd_hh_rank_nbr" to T0, and avoid the join ?

-- 
Justin