[
https://issues.apache.org/jira/browse/PIG-158?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=12603746#action_12603746
]
Santhosh Srinivasan commented on PIG-158:
-----------------------------------------
"Re: Eliminating the Generate Operator": Translating the Generate Operator to
the Accumulator
Instead of eliminating the Generate Operator, we can instead translate the
generate operator to the accumulate operator or overload the POGenerate to
provide the ability to accumulate tuples. The logical plan will remain
unchanged. The logical to physical translator will do the following:
In order to translate the Generate operator, the nested plans which are
currently part of the Generate will be promoted to be a part of the Foreach
operator with the following changes:
1. In the nested plan of Foreach remove any leaves that are not Generate
2. Any expression that is part of the generate (root of the nested plan) which
does not require Generate's input will be moved into a nested plan of Foreach.
3. The remaining expressions of generate will be attached to Generate by
duplicating the graph.
4. The physical translation of Generate will now be the new Accumulate Operator
or POGenerate with the added functionality of being able to accumulate.
> Rework logical plan
> -------------------
>
> Key: PIG-158
> URL: https://issues.apache.org/jira/browse/PIG-158
> Project: Pig
> Issue Type: Sub-task
> Components: impl
> Reporter: Alan Gates
> Assignee: Alan Gates
> Attachments: is_null.patch, logical_operators.patch,
> logical_operators_rev_1.patch, logical_operators_rev_2.patch,
> logical_operators_rev_3.patch, parser_changes.patch, parser_changes_v1.patch,
> parser_changes_v2.patch, parser_changes_v3.patch, parser_changes_v4.patch,
> ParserErrors.txt, udf_fix.patch, udf_funcSpec.patch, udf_return_type.patch,
> user_func_and_store.patch, visitorWalker.patch
>
>
> Rework the logical plan in line with
> http://wiki.apache.org/pig/PigExecutionModel
--
This message is automatically generated by JIRA.
-
You can reply to this email to add a comment to the issue online.
