[
https://issues.apache.org/jira/browse/PIG-953?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=12753843#action_12753843
]
Alan Gates commented on PIG-953:
--------------------------------
-1 to adding an orderPreserving flag on operators. We have no intention of
ever promising that any relational operator beyond Order and Limit preserve
order. The fact that some happen to now (like filter) is a side effect of the
current implementation, not a feature. If we add a flag, it becomes a feature
that we will be expected to maintain.
> Enable merge join in pig to work with loaders and store functions which can
> internally index sorted data
> ---------------------------------------------------------------------------------------------------------
>
> Key: PIG-953
> URL: https://issues.apache.org/jira/browse/PIG-953
> Project: Pig
> Issue Type: Improvement
> Affects Versions: 0.3.0
> Reporter: Pradeep Kamath
> Assignee: Pradeep Kamath
> Attachments: PIG-953.patch
>
>
> Currently merge join implementation in pig includes construction of an index
> on sorted data and use of that index to seek into the "right input" to
> efficiently perform the join operation. Some loaders (notably the zebra
> loader) internally implement an index on sorted data and can perform this
> seek efficiently using their index. So the use of the index needs to be
> abstracted in such a way that when the loader supports indexing, pig uses it
> (indirectly through the loader) and does not construct an index.
--
This message is automatically generated by JIRA.
-
You can reply to this email to add a comment to the issue online.
