Re: pgbench --tuple-size option - Mailing list pgsql-hackers

From Fabien COELHO
Subject Re: pgbench --tuple-size option
Date
Msg-id alpine.DEB.2.10.1408152255110.29316@sto
Whole thread Raw
In response to Re: pgbench --tuple-size option  (Andres Freund <andres@2ndquadrant.com>)
List pgsql-hackers
>>> The custom initialization is to run a manual ALTER after the
>>> initialization.
>>
>> Sure, it can be done this way.
>>
>> I'm not sure about the implication of ALTER on the table storage,
>
> Should be fine in this case.

After some testing and laughing, my conclusion is "not fine at all". The 
"filler" attributes in "pgbench" are by default "EXTENDED", which mean 
possibly compressed... As the the default value is '', the compression, 
when tried for large sizes, performs very well, and the performance is the 
same as with a (declared) smaller tuple:-) Probably not the intention of 
the benchmark designer. Conclusion: I need an ALTER TABLE anyway to change 
the STORAGE. Or maybe pgbench should always do it anyway...

Conclusion 2: I've noted the submission as "rejected" as both you and 
Fujii don't like it, and although I found it useful, but I can do without 
it quite easily.

-- 
Fabien.



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