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From Abdel Hakim Deneche <adene...@maprtech.com>
Subject Re: Apache Drill: How does the plug-in know that an aggregate function is applied
Date Thu, 06 Aug 2015 15:50:37 GMT
Hi Sudip,

I'm not really an expert in this matter but I came recently across
isSkipQuery() method in AbstractRecordReader, it's javadoc states:

*Returns true if reader should skip all of the columns, reporting number of
> records only. Handling of a skip query is storage plugin-specific.*

You can take a look at JSONRecordReader for an example on how to use
isSkipQuery() to optimize the reading.


On Thu, Aug 6, 2015 at 2:01 AM, Sudip Mukherjee <mukherjeesudip1@hotmail.com
> wrote:

> Hi,
> I am using apache drill recently with mongodb and trying to write a basic
> plug-in for apache solr. Wanted to know how does the plug-in know that an
> count(*) query has been applied so that the query to data-source can be
> optimized? Can i get it if I extend  AbstractExprVisitor class?
> Thanks,Sudip Mukherjee


Abdelhakim Deneche

Software Engineer


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