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https://issues.apache.org/jira/browse/HAWQ-492?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15206843#comment-15206843
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Michael Andre Pearce (IG) commented on HAWQ-492:
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Should I look there for to re-open this ticket? Or submit a new?

> PXF Query Push-Down Feature enhancement to enable further push down to 
> Datasource
> ---------------------------------------------------------------------------------
>
>                 Key: HAWQ-492
>                 URL: https://issues.apache.org/jira/browse/HAWQ-492
>             Project: Apache HAWQ
>          Issue Type: Improvement
>          Components: PXF
>            Reporter: Michael Andre Pearce (IG)
>            Assignee: Lei Chang
>
> PXF currently supports push down of filters to the PXF plugin. So that PXF 
> itself only needs to return the fields and rows that match the filters.
> Unfortunately it seems (and it could be simply miss-understanding) is done in 
> a way where by the PXF plugin must retrieve the complete row/entry from the 
> source then the filters are applied. With Query Filter Push-Down feature.
> With a JDBC PXF (https://github.com/kojec/pxf-field/tree/master/jdbc-pxf-ext) 
> this seems to be the case where by the SELECT * FROM table is done. 
> It would be much more efficient if the filter and fields are push down in a 
> way so that the plugin can if in its use case can actually delegate that 
> further down into datasource it is using, and retrieving and applying the 
> filters needed to reduce the data it needs to be pulled back.
> As such the PXF accessor would be able to construct SELECT fieldA fieldB FROM 
> table WHERE fieldA > 6
> It maybe that this is indeed possible, but looking at 
> https://github.com/kojec/pxf-field/tree/master/jdbc-pxf-ext and the API's and 
> documents currently available we cannot see a way to improve this jdbc pxf 
> plugin to achieve this.



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