Bugs item #2817953, was opened at 2009-07-07 13:42 Message generated for change (Comment added) made by johnvanschie You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=482468&aid=2817953&group_id=56967
Please note that this message will contain a full copy of the comment thread, including the initial issue submission, for this request, not just the latest update. Category: XML Group: Pathfinder "stable" Status: Open Resolution: None Priority: 5 Private: No Submitted By: John van Schie (johnvanschie) Assigned to: Sjoerd Mullender (sjoerd) Summary: Empty result returned for updated document Initial Comment: OS: Ubuntu LTs 8.04, x86_64 MonetDB: MonetDB 4.28.4 (Feb2009-SP2) I have a database with one updateable document, bookmarks.xml. After this document has been updated for a couple of times (max 10 times), sometimes queries do not return the expected answer, but return an empty result. The document was created with an update percentage of 10. I could not reproduce the bug by inserting the document in a fresh database and performing updates and queries, but I have a copy of a database that shows the behaviour. I'll send it to Stefan. To reproduce the bug, run MonetDB with the given database folder (it contains the data and the xquery logs). Then continously run the three attached queries in paralel with mclient. Most queries return the correct result, but some return a empty result. ---------------------------------------------------------------------- >Comment By: John van Schie (johnvanschie) Date: 2009-07-10 09:51 Message: You're right, it is not a query log. I tried to recreate the updates by looking at the differences of the original document and the document in the corrupt database, but forgot about possible deletes. It could be very well that deletes were performed, as a delete is executed when a bookmark is 'overwritten', but I do not have any way to recreate it for you. Sorry. ---------------------------------------------------------------------- Comment By: Sjoerd Mullender (sjoerd) Date: 2009-07-09 16:01 Message: I have a feeling this is not the complete log of what happened to this bookmarks.xml document. When I look at the actual database, I see that there are several holes. Since these are not at page boundaries (the document easily fits in a single page), they can only be the result of deleted nodes (or nodes replaced by smaller ones). In your log there are only insert queries. I can run the queries you attached to create a document (I used the bookmarks.xml from your bug #2817414 as initial document), but the result is correct. I have tried this with the May2009-SP1, Feb2009-SP2 and Feb2009 releases. ---------------------------------------------------------------------- Comment By: John van Schie (johnvanschie) Date: 2009-07-09 13:25 Message: Sjoerd, The query log is attached to the bug report. The first update is the creation of a folder element. The other 6 updates, insert the content of another shredded document to the bookmarks file. This other document is a temporary document, and added before the update and deleted after the update. They are _not_ shredded under the same name. We chose for this indirect updates as problems where encountered when inserting a large node. This solution was implemented Aug 2008, so I don't know how relevant this workaround still is. ---------------------------------------------------------------------- Comment By: Sjoerd Mullender (sjoerd) Date: 2009-07-08 18:01 Message: Just for the bookmarks document. For now I'm assuming that the code treats the different document collections that you may have independently. ---------------------------------------------------------------------- Comment By: John van Schie (johnvanschie) Date: 2009-07-08 17:06 Message: Sjoerd, Do you mean the sequence of updates on the bookmarks document or the total series of updates on all updateable documents in the database, as the latter will take me some more time. -- John ---------------------------------------------------------------------- Comment By: Sjoerd Mullender (sjoerd) Date: 2009-07-08 14:55 Message: I got the database from Stefan and quickly analyzed it. It is clear, the database is corrupt. The big question is, how did it get that way? Can you reproduce the sequence of updates that got you into this mess? If so, I'd like to see the original documents and the queries to get to this state. ---------------------------------------------------------------------- You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=482468&aid=2817953&group_id=56967 ------------------------------------------------------------------------------ Enter the BlackBerry Developer Challenge This is your chance to win up to $100,000 in prizes! For a limited time, vendors submitting new applications to BlackBerry App World(TM) will have the opportunity to enter the BlackBerry Developer Challenge. See full prize details at: http://p.sf.net/sfu/Challenge _______________________________________________ Monetdb-bugs mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/monetdb-bugs
