I have file a JIRA issue at https://issues.apache.org/jira/browse/DERBY-2144
Army-4 wrote: > > Suresh Thalamati wrote: >> By doing quick scan of the code, I think during the query optimization >> Derby opens all the tables and all the indexes on each table to estimate >> the costs and those containers are not closed until the nested >> transaction used to compile the query is closed. Because the containers >> used to estimate the cost are not closed, corresponding container files >> can not be closed, so the container cache (file handle cache ) keep >> growing. > > I'm not very familiar with the costing mechanism of the optimizer (most of > the > work I've done just assumes that the costs are correct), but I spent some > time > looking at the cost estimation code and I agree with Suresh: as far as I > can > tell, it looks like the optimizer opens the containers for base tables and > indexes in the query but does not close them until compilation completes. > >> May be it is not really required to keep all containers open >> until the end of compiling the query. > > It may be possible to add logic that closes and re-opens the containers > during > optimization as they are needed. Note, though, that the containers are > deliberately cached in the current code and the assumption appears to be > that > they will remain open throughout optimization. So I think any changes in > this > area could be non-trivial and would have to take into consideration > potential > performance effects. But that said, I willingly admit that I know very > little > about the relevant parts of the Derby code, so I could be wrong. > > In any event, maybe the best thing to do here is to file a Jira > enhancement for > tracking purposes? If you (Suraj) choose to do so, the zip file > containing the > reproduction could be attached to the Jira issue for ease of reference. > > > But now the big problem is my application does not support jdk15. Is > > there a way we can have a fix for the above issue with using the jdk14 > ? > > The first step toward resolving the problem is to file a Jira issue: > > http://db.apache.org/derby/DerbyBugGuidelines.html > > Once that's done, the easiest way to get a fix into the codeline is to > contribute the changes yourself :) If you have the time and inclination > to work > on this issue, you should feel free to join the community: > > http://wiki.apache.org/db-derby/DerbyDev > > Otherwise you can just file the Jira issue and then anyone who is > interested can > pick it up and work to resolve it... > > Army > > > -- View this message in context: http://www.nabble.com/Error-when-executing-query%3Acom.ibm.websphere.ce.cm.StaleConnectionException%3A-Meta-data-for-Container-org.apache.derby.impl.store.raw.data.RAFContainer%406fd148fc-could-not-be-accessed-tf2634449.html#a7694568 Sent from the Apache Derby Users mailing list archive at Nabble.com.
