GitHub user sachouche opened a pull request: https://github.com/apache/drill/pull/1060
DRILL-5846: Improve parquet performance for Flat Data Types Performance improvements for the Parquet Scanner (Flat Data Types). The are two flags to control this performance enhancement (disabled by default): Option I - Config Name: store.parquet.flat.reader.bulk Config Type : boolean Description : Enables bulk processing to minimize memory checks and improve JVM HotSpot optimizations Option II - Config Name: scan.optimized.implicit.columns Config Type : boolean Description : Memory optimization when storing duplicate value (implicit columns have duplicate values within a batch). Code profiling indicated this step represented one third of Parquet processing (when implicit columns are processed). You can merge this pull request into a Git repository by running: $ git pull https://github.com/sachouche/drill drill-parquet-improv Alternatively you can review and apply these changes as the patch at: https://github.com/apache/drill/pull/1060.patch To close this pull request, make a commit to your master/trunk branch with (at least) the following in the commit message: This closes #1060 ---- commit 0a3a8b053be85c570ff24237d4737f37668383bd Author: Salim Achouche <sachouc...@gmail.com> Date: 2017-12-04T01:53:08Z DRILL-5846: Improve parquet performance for Flat Data Types ---- ---