Hi.
From what you are describing here, with the spec references, the current behavior looks like a bug (may be a performance bug only, but still).
Thanks, Pawel. On 02/24/2012 12:02 PM, Kevin Sutter wrote:
Hi, I recently came across this issue... OpenJPA generates SQL with an "Order By" clause whenever the declared type is a List -- and without an OrderColumn or OrderBy annotation. All that is required is for the declared type to be List (vs a Collection, Set, etc) and we insert the "Order By" clause. OpenJPA has been doing this for a long, long time (since day one?). I did find this JIRA (https://issues.apache.org/jira/browse/OPENJPA-710) where at least we decided that it should only be done for List types. But, that was back in Sept 2008. Before that, we were doing it for all collection-based relationships... So, my question is, what type of impact will this have on our users? I'd like to correct this. From a JPA processing perspective, it's a nit. But, there is an associated cost with the databases and we're always concerned about the performance of our generated SQL. The use of this "Order By" is not a requirement of the JPA specification. As a matter of fact, they have a footnote where it explains not to rely on any given order unless you are using an OrderColumn or OrderBy construct. *[3] Portable applications should not expect the order of a list to be maintained across persistence contexts unless the OrderColumn* *construct is used or unless the OrderBy construct is used and the modifications to the list observe the specified ordering.* What do you think? Is anyone aware of a dependency where this type of change would affect them? Even if I make this change, I would still provide a Compatibility switch that would allow you to get back to the old (incorrect) behavior. It's just that since this processing has been there for so long, it makes me a little nervous making this type of change. Thoughts? Kevin
