Re: Performance issue

On Mon, 15 Jun 2020 at 10:46, Nagaraj Raj <nagaraj(dot)sf(at)yahoo(dot)com> wrote:
> CREATE TABLE test1
> (
...

> CONSTRAINT pk_i_entity_proxy_id PRIMARY KEY (individual_entity_proxy_id)
>
> );

> CREATE TABLE test2
> (
...

> CONSTRAINT pk_entity_proxy_id PRIMARY KEY (individual_entity_proxy_id)
> );
>
>
> User query:
>
> explain analyze select COUNT(*) as "DII_1"
> from ( select distinct table0."individual_entity_proxy_id" as "INDIVIDUAL_ENTITY_PROXY_ID"
> from test1 table0
> inner join test2 table1
> on table0."individual_entity_proxy_id" = table1."individual_entity_proxy_id"

Why do you use "select distinct". It seems to me that you're putting a
distinct clause on the primary key of test1 and joining to another
table in a way that cannot cause duplicates.

I imagine dropping that distinct will speed up the query quite a bit.

David