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https://issues.apache.org/jira/browse/CRUNCH-278?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13792680#comment-13792680
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Josh Wills commented on CRUNCH-278:
-----------------------------------
I don't think it would prevent using the library functions-- it would just look
like:
PCollection<K> stuff = ...;
PTable<K, V> cnt = stuff.count();
ReadableSourceBundle<Pair<K, V>> = cnt.toBundle();
i.e., you would just do whatever transforms you wanted to apply before
converting the PCollection to a bundle.
That said, I think that if we had an instance like this, we would be inclined
to kick off an MR job vs. just reading the data in memory and doing the
count/aggregation ourselves using the in-memory pipeline. Maybe an option on
the API to control that?
> Improvements to MapsideJoin code
> --------------------------------
>
> Key: CRUNCH-278
> URL: https://issues.apache.org/jira/browse/CRUNCH-278
> Project: Crunch
> Issue Type: Bug
> Components: Core, MapReduce Patterns
> Reporter: Josh Wills
> Assignee: Josh Wills
> Attachments: CRUNCH-278.patch
>
>
> The fact that we have special-case code in the MapsideJoinStrategy for the
> in-memory and MR-based Pipeline instances has always bugged me, so I set out
> to eliminate the distinction between the two impls by creating a new
> interface, ReadableSourceBundle<T>, that encapsulates the MR and in-memory
> specific logic for doing mapside joins in order to remove the special-case
> code in MapsideJoinStrategy and hopefully make other implementations that use
> our mapside-join patterns much easier to test.
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