Re: O(n^2) aggregates

From: "Pavel Stehule" <pavel(dot)stehule(at)gmail(dot)com>
To: "Gregory Stark" <stark(at)enterprisedb(dot)com>
Cc: "pgsql-hackers list" <pgsql-hackers(at)postgresql(dot)org>
Subject: Re: O(n^2) aggregates
Date: 2007-12-10 17:05:14
Message-ID: 162867790712100905t316c5eb9y873176074a14de92@mail.gmail.com
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Hello

>
> select count(*)
> from huge
> where h = any ((select arrayize( (1+random()*300000000)::integer )
> from generate_series(1,1000)
> )::integer[])
>

select array(select (1+random()*300000000):: integer from
generate_series(1,40000));
Time: 111,807 ms

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