Hi Andy,
I think this is a good idea and we should add this to the next release!
I agree to go for option 3 and add a method to the Query API to abort
query execution. BTW, maybe abort is a better method name for the
method, what do you think?
I'm wondering whether there are any implementation issues. AFAIK, there
is no standard JDBC API to abort a a running JDBC query. So how about
allowing the method to throw a JDOUnsupportedOptionException in case it
cannot be implemented for the underlying database?
Could you please file a "New Feature" JIRA for this?
Regards Michael
JDO doesn't have a mechanism to stop queries from overrunning. JPA2 now allows
a persistence property to allow timing them out, and most JDO implementations
have allowed this as an extension since JDO1. It would make sense for JDO
(2.3) to have the same or a variation. Some ideas
Option1 :
Simple PMF property "javax.jdo.option.queryTimeout" to specify the number of
millisecs (or secs) before any query is timed out. Throw a
QueryTimeoutException (extends JDOException) when the timeout happens
Option2 :
as Option1, plus setTimeout() on Query to define it on a per query basis.
Option3 :
as Option2, plus we add cancel() on Query so that users can cancel long
running queries programmatically, throwing a QueryInterruptedException
(extends JDOUserException). The cancel would apply to all currently running
invoked queries from that Query instance.
I'd go for option 3 since it provides full control in one change and we won't
need to revisit the area later to add extra control. Comments ?
--
*Michael Bouschen*
*Prokurist*
akquinet t...@spree GmbH
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Email: michael.bousc...@akquinet.de
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