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https://issues.apache.org/jira/browse/OAK-6269?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16187886#comment-16187886
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Alex Deparvu commented on OAK-6269:
-----------------------------------
added a missing license header on {{OakIndexFile}} with
http://svn.apache.org/viewvc?rev=1810337&view=rev
> Support non chunk storage in OakDirectory
> -----------------------------------------
>
> Key: OAK-6269
> URL: https://issues.apache.org/jira/browse/OAK-6269
> Project: Jackrabbit Oak
> Issue Type: Improvement
> Components: lucene
> Reporter: Chetan Mehrotra
> Assignee: Vikas Saurabh
> Fix For: 1.8, 1.7.9
>
> Attachments:
> 0001-OAK-6269-Support-non-chunk-storage-in-OakDirectory.patch,
> 0002-OAK-6269-Support-non-chunk-storage-in-OakDirectory.patch,
> 0003-OAK-6269-Support-non-chunk-storage-in-OakDirectory.patch,
> S3DsSupport.patch, s3Files.false.txt, s3Files.true.txt
>
>
> Logging this issue based on offline discussion with [~catholicon].
> Currently OakDirectory stores files in chunk of 1 MB each. So a 1 GB file
> would be stored in 1000+ chunks of 1 MB.
> This design was done to support direct usage of OakDirectory with Lucene as
> Lucene makes use of random io. Chunked storage allows it to seek to random
> position quickly. If the files are stored as Blobs then its only possible to
> access via streaming which would be slow
> As most setup now use copy-on-read and copy-on-write support and rely on
> local copy of index we can have an implementation which stores the file as
> single blob.
> *Pros*
> * Quite a bit of reduction in number of small blobs stored in BlobStore.
> Which should reduce the GC time specially for S3
> * Reduced overhead of storing a single file in repository. Instead of array
> of 1k blobids we would be stored a single blobid
> * Potential improvement in IO cost as file can be read in one connection and
> uploaded in one.
> *Cons*
> It would not be possible to use OakDirectory directly (or would be very slow)
> and we would always need to do local copy.
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