| From: | Lukas Kahwe Smith <smith(at)pooteeweet(dot)org> |
|---|---|
| To: | Bruce Momjian <bruce(at)momjian(dot)us> |
| Cc: | pgsql-hackers(at)postgresql(dot)org |
| Subject: | Re: Simple Column reordering |
| Date: | 2007-02-23 23:39:42 |
| Message-ID: | 45DF7B3E.7090707@pooteeweet.org |
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| Lists: | pgsql-hackers |
Bruce Momjian wrote:
> Lukas Kahwe Smith wrote:
>> Simon Riggs wrote:
>>
>>> If this is standards-breaking as you say, I would withdraw immediately.
>>> I checked the SQL standard and could not see how this would do so. The
>>> standard states SELECT * would return columns in order; it doesn't say
>>> what that order should be, nor does CREATE TABLE enforce the ordering to
>>> be the same as it has specified, AFAICS. Please correct me and I will
>>> withdraw. Practical issues seem far stronger drivers than standards
>>> issues here, which is why the parameter would default=off.
>> I did not follow the entire thread. I just wanted to point out that IIRC
>> MS SQL Server (and maybe also Sybase) do automatically optimize the
>> internal order of how columns are stored to move fixed length (which
>> also means non NULLable for these two servers) columns to the left.
>> Maybe this will serve as a reference point (not necessarily for
>> standards compliance of course).
>
> And that optimized ordering shows up with SELECT *?
no .. like i said its just the internal order ..
I think I learned this piece of information from reading "SQL
performance tuning" by Peter and Trudy .. dont have the book here right
now to give a page number.
regards,
Lukas
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