GitHub user bersprockets opened a pull request: https://github.com/apache/spark/pull/21043
[SPARK-23963] [SQL] Properly handle large number of columns in query on text-based Hive table ## What changes were proposed in this pull request? TableReader would get disproportionately slower as the number of columns in the query increased. I fixed the way TableReader was looking up metadata for each column in the row. Previously, it had been looking up this data in linked lists, accessing each linked list by an index (column number). Now it looks up this data in arrays, where indexing by column number works better. ## How was this patch tested? All sbt unit tests python sql tests You can merge this pull request into a Git repository by running: $ git pull https://github.com/bersprockets/spark tabreadfix Alternatively you can review and apply these changes as the patch at: https://github.com/apache/spark/pull/21043.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 #21043 ---- commit 26715a8110be1d72f18604dfd4ae74a5a56d9878 Author: Bruce Robbins <bersprockets@...> Date: 2018-04-11T05:05:12Z Initial commit for testing ---- --- --------------------------------------------------------------------- To unsubscribe, e-mail: reviews-unsubscr...@spark.apache.org For additional commands, e-mail: reviews-h...@spark.apache.org