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* Variable versus constrant size tuples
@ 2011-08-19 09:03 Krzysztof Chodak <krzysztof.chodak@gmail.com>
0 siblings, 2 replies; 4+ messages in thread
From: Krzysztof Chodak @ 2011-08-19 09:03 UTC (permalink / raw)
To: pgsql-performance
Is there any performance benefit of using constant size tuples?
^ permalink raw reply [nested|flat] 4+ messages in thread
* Re: Variable versus constrant size tuples
@ 2011-08-19 15:03 Andy Colson <andy@squeakycode.net>
parent: Krzysztof Chodak <krzysztof.chodak@gmail.com>
1 sibling, 0 replies; 4+ messages in thread
From: Andy Colson @ 2011-08-19 15:03 UTC (permalink / raw)
To: Krzysztof Chodak <krzysztof.chodak@gmail.com>; +Cc: pgsql-performance
On 8/19/2011 4:03 AM, Krzysztof Chodak wrote:
> Is there any performance benefit of using constant size tuples?
>
If you are referring to varchar(80) vs text, then no, there is no benefit.
-Andy
^ permalink raw reply [nested|flat] 4+ messages in thread
* Re: Variable versus constrant size tuples
@ 2011-08-19 15:03 Merlin Moncure <mmoncure@gmail.com>
parent: Krzysztof Chodak <krzysztof.chodak@gmail.com>
1 sibling, 1 reply; 4+ messages in thread
From: Merlin Moncure @ 2011-08-19 15:03 UTC (permalink / raw)
To: Krzysztof Chodak <krzysztof.chodak@gmail.com>; +Cc: pgsql-performance
On Fri, Aug 19, 2011 at 4:03 AM, Krzysztof Chodak
<krzysztof.chodak@gmail.com> wrote:
> Is there any performance benefit of using constant size tuples?
not really. If your tuple size is under a known maximum length, then
a toast table doesn't have to be created. that's a pretty minor
detail though.
merlin
^ permalink raw reply [nested|flat] 4+ messages in thread
* Re: Variable versus constrant size tuples
@ 2011-08-19 15:19 Krzysztof Chodak <krzysztof.chodak@gmail.com>
parent: Merlin Moncure <mmoncure@gmail.com>
0 siblings, 0 replies; 4+ messages in thread
From: Krzysztof Chodak @ 2011-08-19 15:19 UTC (permalink / raw)
To: Merlin Moncure <mmoncure@gmail.com>; andy@squeakycode.net; +Cc: pgsql-performance
Thank you. Now I see that page consists of record pointers list build
from offset and length so there is no benefit of having constant
length here.
On Fri, Aug 19, 2011 at 17:03, Merlin Moncure <mmoncure@gmail.com> wrote:
> On Fri, Aug 19, 2011 at 4:03 AM, Krzysztof Chodak
> <krzysztof.chodak@gmail.com> wrote:
>> Is there any performance benefit of using constant size tuples?
>
> not really. If your tuple size is under a known maximum length, then
> a toast table doesn't have to be created. that's a pretty minor
> detail though.
>
> merlin
>
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2011-08-19 09:03 Variable versus constrant size tuples Krzysztof Chodak <krzysztof.chodak@gmail.com>
2011-08-19 15:03 ` Andy Colson <andy@squeakycode.net>
2011-08-19 15:03 ` Merlin Moncure <mmoncure@gmail.com>
2011-08-19 15:19 ` Krzysztof Chodak <krzysztof.chodak@gmail.com>
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