Details
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Bug
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Status: Resolved
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Major
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Resolution: Fixed
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None
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None
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None
Description
Currently, the scan operator will read all the columns from the data source, and pass all the columns to down-stream operator.
In order to improve performance of Drill query, we should instead push the project operation into scan operator. The scan operator will take as an input a list of columns required to retrieve. If the query only refers a subset of columns, the scan operator will only have to retrieve values for the column in the list.
It's expected to see performance improvement once project push-down is supported.
Attachments
Attachments
Issue Links
- is broken by
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DRILL-631 Trivial project removal with pushdown breaks information schema
- Resolved