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Jukka Zitting updated JCR-926: ------------------------------ Attachment: DataStore2.patch Attached a prototype patch that integrates the data store concept in Jackrabbit. The integration is very ugly at this stage and the attached code is definitely not meant for inclusion as-is. For very rough performance testing I created a simple test application that creates a versionable folder with 100 files in it, each containing about 270kB of application/octet-stream data. Once populated, the entire folder was checked into the version store. The numbers, averaged over a couple of test runs, are: Current svn trunk: 100 added files: 5625 milliseconds checkin everything: 11094 milliseconds With this patch: 100 added files: 2750 milliseconds checkin everything: 1906 milliseconds > Global data store for binaries > ------------------------------ > > Key: JCR-926 > URL: https://issues.apache.org/jira/browse/JCR-926 > Project: Jackrabbit > Issue Type: New Feature > Components: core > Reporter: Jukka Zitting > Attachments: DataStore.patch, DataStore2.patch > > > There are three main problems with the way Jackrabbit currently handles large > binary values: > 1) Persisting a large binary value blocks access to the persistence layer for > extended amounts of time (see JCR-314) > 2) At least two copies of binary streams are made when saving them through > the JCR API: one in the transient space, and one when persisting the value > 3) Versioining and copy operations on nodes or subtrees that contain large > binary values can quickly end up consuming excessive amounts of storage space. > To solve these issues (and to get other nice benefits), I propose that we > implement a global "data store" concept in the repository. A data store is an > append-only set of binary values that uses short identifiers to identify and > access the stored binary values. The data store would trivially fit the > requirements of transient space and transaction handling due to the > append-only nature. An explicit mark-and-sweep garbage collection process > could be added to avoid concerns about storing garbage values. > See the recent NGP value record discussion, especially [1], for more > background on this idea. > [1] > http://mail-archives.apache.org/mod_mbox/jackrabbit-dev/200705.mbox/[EMAIL > PROTECTED] -- This message is automatically generated by JIRA. - You can reply to this email to add a comment to the issue online.