| From: | Bastiaan Olij <bastiaan(at)basenlily(dot)me> |
|---|---|
| To: | pgsql-performance(at)postgresql(dot)org |
| Subject: | Re: Speed of exist |
| Date: | 2013-02-19 10:18:55 |
| Message-ID: | 5123518F.30206@basenlily.me |
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| Thread: | |
| Lists: | pgsql-performance |
Hi Pavel,
That is what I've done in this particular case but there are parts where
I use exist checks in this way that are very cumbersome to write out
like that so I'm hoping there is a way to make the optimizer work with
existence checks in this way.
Cheers,
Bastiaan Olij
On 19/02/13 6:39 PM, Pavel Stehule wrote:
> 2013/2/19 Bastiaan Olij <bastiaan(at)basenlily(dot)me>:
>> Hi Andy,
>>
>> I've tried that with the same result. One subquery works beautifully,
>> two subqueries with an OR and it starts to do a sequential scan...
> try to rewrite OR to two SELECTs joined by UNION ALL
>
> Pavel
>
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