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Re: (ITS#6612) Back SQL / Mysql / InnoDB



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I did some more research on this issue. I found that the problem can be 
solved more addequately by adding a configuration option called 
transaction_model with the following options 
default|read_committed|read_uncommitted|repeatable_read|serialize. The 
option default uses the database default, current OpenLDAP 
implementation, while the other 4 options set the transaction level 
explicitly.

Since InnoDB has repeatable read as default, this prevents from updating 
resultsets. "For consistent reads, there is an important difference from 
the READ COMMITTED isolation level: All consistent reads within the same 
transaction read the snapshot established by the first read."
http://dev.mysql.com/doc/refman/5.0/en/set-transaction.html

SQL 2000 by Microsoft and PostgreSQL have read committed as default option.
http://msdn.microsoft.com/en-us/library/aa259216%28SQL.80%29.aspx
http://www.postgresql.org/docs/8.1/static/transaction-iso.html


-- 
* Frederik Bosch*
Partner - Genkgo

email: f.bosch@genkgo.nl <mailto:f.bosch@genkgo.nl>
tel: +31(0)6 241 97 443

*Genkgo V.o.f.* <http://www.genkgo.nl>
adres: Rooseveltlaan 162-II
postcode : 1078 NT Amsterdam
web: www.genkgo.nl <http://www.genkgo.nl>


Genkgo logo <http://www.genkgo.nl>

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Genkgo staat geregistreerd bij de Kamer van Koophandel onder nummer 
24296168

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I did some more research on this issue. I found that the problem can be
solved more addequately by adding a configuration option called
transaction_model with the following options
default|read_committed|read_uncommitted|repeatable_read|serialize. The
option default uses the database default, current OpenLDAP
implementation, while the other 4 options set the transaction level
explicitly.<br>
<br>
Since InnoDB has repeatable read as default, this prevents from
updating resultsets. "For consistent reads, there is an important
difference from the READ COMMITTED isolation level: All consistent
reads within the same transaction read the snapshot established by the
first read."<br>
<a class="moz-txt-link-freetext" href="http://dev.mysql.com/doc/refman/5.0/en/set-transaction.html";>http://dev.mysql.com/doc/refman/5.0/en/set-transaction.html</a><br>
<br>
SQL 2000 by Microsoft and PostgreSQL have read committed as default
option.<br>
<a class="moz-txt-link-freetext" href="http://msdn.microsoft.com/en-us/library/aa259216%28SQL.80%29.aspx";>http://msdn.microsoft.com/en-us/library/aa259216%28SQL.80%29.aspx</a><br>
<a class="moz-txt-link-freetext" href="http://www.postgresql.org/docs/8.1/static/transaction-iso.html";>http://www.postgresql.org/docs/8.1/static/transaction-iso.html</a><br>
<br>
<br>
<div class="moz-signature">-- <br>
<div class="vcard"
 style="border-top: 1px dotted rgb(153, 153, 153) ! important; padding: 8px ! important; line-height: 14px ! important; font-family: 'Lucida Grande',Verdana,Arial,Sans-Serif ! important; font-size: 10px ! important; color: rgb(85, 85, 85) ! important;">
<div
 style="border-bottom: 1px dotted rgb(153, 153, 153) ! important; margin: 6px 0pt ! important; width: 420px ! important;">
<strong
 style="color: rgb(0, 170, 173) ! important; font-size: 12px ! important;">
<span class="n">Frederik Bosch</span></strong><br>
<span class="role">Partner</span> - Genkgo<br>
<br>
email: <a class="email" href="mailto:f.bosch@genkgo.nl";
 style="color: rgb(0, 170, 173) ! important; text-decoration: none ! important;">f.bosch@genkgo.nl</a><br>
tel: <span class="tel cell">+31(0)6 241 97 443</span><br>
<br>
<a class="organization-name" href="http://www.genkgo.nl";
 style="color: rgb(0, 170, 173) ! important; text-decoration: none ! important;"><strong>Genkgo
V.o.f.</strong></a><br>
<span class="adr" style="color: rgb(85, 85, 85) ! important;">adres:
Rooseveltlaan 162-II<br>
postcode : <span class="postal-code">1078 NT</span> <span
 class="locality">Amsterdam</span> <br>
<span class="url">web: <a href="http://www.genkgo.nl";
 style="color: rgb(0, 170, 173) ! important; text-decoration: none ! important;">www.genkgo.nl</a><br>
<br>
<br>
<a href="http://www.genkgo.nl";><img class="logo"
 src="cid:part1.09000506.03080001@genkgo.nl" alt="Genkgo logo"
 style="border: 0pt none  ! important;"></a><br>
<br>
</span></span></div>
<div class="note"
 style="width: 420px ! important; line-height: 14px; font-family: 'Lucida Grande',Verdana,Arial,Sans-Serif ! important; font-size: 10px ! important; color: rgb(85, 85, 85) ! important;">
Dit e-mailbericht is bestemd voor de geadresseerde(n) en kan
vertrouwelijk zijn. Gebruik door anderen dan de geadresseerde(n) is
verboden. Als dit bericht niet voor u bestemd is, wordt u vriendelijk
verzocht dit aan de afzender te melden en het bericht te vernietigen. <br>
<br>
Genkgo staat geregistreerd bij de Kamer van Koophandel onder nummer
24296168 </div>
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