[JDO-623] Query cancel and timeout support

• Type: New Feature
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Fix Version/s: JDO 3 (3.0)
• Component/s: api, tck
• Assignee: Michael Bouschen
• Reporter: Andy Jefferson
• Created: 06/Feb/09 19:37
• Updated: 14/Jun/10 11:02
• Resolved: 02/Apr/10 19:45

Description

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. I propose having the following

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.

Add methods Query.setTimeout(int), Query.getTimeout() to allow setting/retrieving the timeout interval on a per-query basis.

Add method Query.cancel() to cancel any running query. If an implementation doesn't support cancelling of queries then it should throw a JDOUnsupportedOptionException. Any query execute() that is cancelled will throw a QueryInterruptedException (extends JDOUserException).