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Marcel Reutegger commented on JCR-1213: --------------------------------------- Here are my test results. I had to reduce the number of test nodes because I exactly saw what Ard just described. Currently all hits are path checked, hence the poor performance in any test run. http://people.apache.org/~mreutegg/2007/11/JCR-1213/100k-test.html Initially the performance with the current code base is not that bad, but as soon as more DocIds across index segments are created the performance drops drastically. As you can see with both Ards and my patch the performance remains stable. > UUIDDocId cache does not work properly because of weakReferences in > combination with new instance for combined indexreader > --------------------------------------------------------------------------------------------------------------------------- > > Key: JCR-1213 > URL: https://issues.apache.org/jira/browse/JCR-1213 > Project: Jackrabbit > Issue Type: Improvement > Components: query > Affects Versions: 1.3.3 > Reporter: Ard Schrijvers > Fix For: 1.4 > > Attachments: JCR-1213-ckiehl.txt, JCR-1213-mreutegg.patch, > JCR-1213.patch, JCR1213Test.java > > > Queries that use ChildAxisQuery or DescendantSelfAxisQuery make use of > getParent() functions to know wether the parents are correct and if the > result is allowed. The getParent() is called recursively for every hit, and > can become very expensive. Hence, in DocId.UUIDDocId, the parents are cached. > Currently, docId.UUIDDocId's are cached by having a WeakRefence to the > CombinedIndexReader, but, this CombinedIndexReader is recreated all the time, > implying that a gc() is allowed to remove the 'expensive' cache. > A much better solution is to not have a weakReference to the > CombinedIndexReader, but to a reference of each indexreader segment. This > means, that in getParent(int n) in SearchIndex the return > return id.getDocumentNumber(this) needs to be replaced by return > id.getDocumentNumber(subReaders[i]); and something similar in > CachingMultiReader. > That is all. Obviously, when a node/property is added/removed/changed, some > parts of the cached DocId.UUIDDocId will be invalid, but mainly small indexes > are updated frequently, which obviously are less expensive to recompute. -- This message is automatically generated by JIRA. - You can reply to this email to add a comment to the issue online.