Dear MonetDB Team,<div><br></div><div>We&#39;re starting to exercise our MonetDB installation more heavily now and I&#39;ve run into a strange issue where I get an occasional &quot;COMMIT: failed&quot; message.</div><div><br>
</div><div>It seems that the conditions required to produce this are:</div><div><br></div><div>- Concurrently inserting into two different tables</div><div>- At the same time, issuing a SELECT COUNT(*) against either of those tables</div>
<div><br></div><div>I&#39;ve logged a bug with more detailed information, including a Java test case:</div><div><br></div><div><a href="http://bugs.monetdb.org/show_bug.cgi?id=3210">http://bugs.monetdb.org/show_bug.cgi?id=3210</a></div>
<div><br></div><div>I&#39;m only just starting my investigation, but I suspect that COUNT(*) may be the culprit, since other selects like SELECT * don&#39;t seem to have this problem.</div><div><br></div><div>Does this ring any bells?  Are there any special optimizations for COUNT(*) that bypass the underlying BAT and/or have side effects on some shared table somewhere that could be causing a concurrency violation?</div>
<div><br></div><div>Thanks,<br clear="all"><div><br></div>-- <br><br><div>Percy Wegmann</div><div>+1 512 637 8500 ext 148</div><br>
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