| From: | Karl Denninger <karl(at)denninger(dot)net> |
|---|---|
| To: | Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> |
| Cc: | Merlin Moncure <mmoncure(at)gmail(dot)com>, Josh Berkus <josh(at)agliodbs(dot)com>, pgsql-performance(at)postgresql(dot)org |
| Subject: | Re: Planner question - "bit" data types |
| Date: | 2009-09-05 21:39:45 |
| Message-ID: | 4AA2DAA1.1030006@denninger.net |
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| Thread: | |
| Lists: | pgsql-performance |
Tom Lane wrote:
> Karl Denninger <karl(at)denninger(dot)net> writes:
>
>> That doesn't help in this case as the returned set will typically be
>> quite large, with the condition typically being valid on anywhere from
>> 10-80% of the returned tuples.
>>
>
> In that case you'd be wasting your time to get it to use an index
> for the condition anyway. Maybe you need to take a step back and
> look at the query as a whole rather than focus on this particular
> condition.
>
> regards, tom lane
>
>
The query, sans this condition, is extremely fast and contains a LOT of
other conditions (none of which cause trouble.)
It is only attempting to filter the returned tuples on the permission
bit(s) involved that cause trouble.
-- Karl
| Attachment | Content-Type | Size |
|---|---|---|
| karl.vcf | text/x-vcard | 124 bytes |
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