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List:       kde-pim
Subject:    Re: [Kde-pim] Review Request 121310: Optimize queries: Do not retrieve known key used in the conditi
From:       Daniel_Vrátil <dvratil () redhat ! com>
Date:       2014-12-02 15:15:17
Message-ID: 20141202151517.22787.77425 () probe ! kde ! org
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This is an automatically generated e-mail. To reply, visit:
https://git.reviewboard.kde.org/r/121310/#review71180
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I'm willing to bet that DBs can optimize these cases internally, so the only benefit \
would really be less data transmitted between DB and application.

But won't the fact, that each column has to be stored in a new variable cause the \
code to actually be slower than transmitting few more bytes to and from DB? The patch \
itself is OK, but I'm just wondering if there's actually any gain?

- Daniel Vrátil


On Dec. 1, 2014, 2:21 p.m., Milian Wolff wrote:
> 
> -----------------------------------------------------------
> This is an automatically generated e-mail. To reply, visit:
> https://git.reviewboard.kde.org/r/121310/
> -----------------------------------------------------------
> 
> (Updated Dec. 1, 2014, 2:21 p.m.)
> 
> 
> Review request for Akonadi, Daniel Vrátil and Volker Krause.
> 
> 
> Repository: akonadi
> 
> 
> Description
> -------
> 
> There is no point in doing a select like:
> 
> SELECT foo, bar FROM table WHERE foo = needle;
> 
> That can be rewritten to say
> 
> SELECT bar FROM table WHERE foo = needle;
> 
> This reduces the data traffic with the mysql server.
> 
> 
> Diffs
> -----
> 
> server/src/storage/entities.xsl 94712933564a8f6c1bf99502e4af837f5934d41e 
> 
> Diff: https://git.reviewboard.kde.org/r/121310/diff/
> 
> 
> Testing
> -------
> 
> it works!
> 
> 
> Thanks,
> 
> Milian Wolff
> 
> 

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