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https://issues.apache.org/jira/browse/DBCP-357?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13903527#comment-13903527
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Bernd Eckenfels commented on DBCP-357:
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I think it is good to have different validators. And JDBC4 isValid() can be one
of them.
However I advice against using this at the only method. For Oracle drivers for
example the isValid() method does internally use a sinple select statement (and
it does actually NOT use a prepared statement). If a timeout is specified it is
even worse at it kicks of a background thread (on each isInvalid(int)
invocation). The Oracle implementation is therefore so bad (as of today), it is
much better to use the sql method (with PS).
BTW: there might be some possibility for optimizations if you have a reset
statement (like rollback() and setAutocommit()). If those are sent to the DB
they can replace the valid check in some conditions.
> Connection validationQuery mechanism should be replaced by new method
> connection#isValid()
> ------------------------------------------------------------------------------------------
>
> Key: DBCP-357
> URL: https://issues.apache.org/jira/browse/DBCP-357
> Project: Commons Dbcp
> Issue Type: Improvement
> Affects Versions: 1.4, 1.4.1
> Reporter: Philippe Mouawad
> Labels: PERFORMANCE
> Fix For: 2.0
>
>
> Hello,
> Current method of connection validation relies on validationQuery.
> This method has a rather big performance impact on the DB (CPU, for example
> 3% with SELECT 1 FROM DUAL even with Oracle 10G FAST DUAL) and make an
> additional query for each borrow (when testOnBorrow is true).
> Wouldn't it be better to use new JDBC 4 method isValid which relies on Driver
> check ? (Oracle would for example use its internal method ping)
> Thank you
> Philippe
> http://www.ubik-ingenierie.com
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