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https://issues.apache.org/jira/browse/CRUNCH-216?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
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Gabriel Reid updated CRUNCH-216:
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Attachment: CRUNCH-216b.patch
About reversing both left and right outer joins, only one outer join type is
supported (left-outer for the legacy mapside join, and right-outer for the
transposed version). This is because there are multiple replicas of the
in-memory side of the join, so it's not currently possible to emit a single
copy of each unmatched value from the in-memory side of the join.
I've made the only reversing of the right-outer join on the transposed version
more explicit in this patch, and removed the factory methods for legacy
instances of MapsideJoinStrategy.
> Transpose arguments in MapsideJoinStrategy.join
> -----------------------------------------------
>
> Key: CRUNCH-216
> URL: https://issues.apache.org/jira/browse/CRUNCH-216
> Project: Crunch
> Issue Type: Improvement
> Reporter: Gabriel Reid
> Attachments: CRUNCH-216.patch, CRUNCH-216b.patch
>
>
> The MapsideJoinStrategy currently specifies that the smaller table in the
> join (i.e. the table to be replicated and loaded in memory) should be on the
> right-hand side of the join.
> This is the opposite of what is done in all other join strategies, making it
> impossible to just switch out another join strategy for a
> MapsideJoinStrategy. The MapsideJoinStrategy could be brought in line with
> the other JoinStrategies to expect the smaller of two tables to be provided
> as the left-side table.
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