[ https://issues.apache.org/jira/browse/SPARK-26935?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]
Sean Owen resolved SPARK-26935. ------------------------------- Resolution: Fixed Fix Version/s: 3.0.0 Issue resolved by pull request 23830 [https://github.com/apache/spark/pull/23830] > Skip DataFrameReader's CSV first line scan when not used > -------------------------------------------------------- > > Key: SPARK-26935 > URL: https://issues.apache.org/jira/browse/SPARK-26935 > Project: Spark > Issue Type: Improvement > Components: SQL > Affects Versions: 2.4.0 > Environment: Spark Version 2.4.0 > Linux kernel 4.9.0-8-amd64 on Debian 9 > Docker container on Google Kubernetes Engine VM (n1-standard-8) > > Reporter: Douglas Colkitt > Assignee: Douglas Colkitt > Priority: Minor > Labels: easyfix, performance, pull-request-available > Fix For: 3.0.0 > > Original Estimate: 1h > Remaining Estimate: 1h > > DataFrameReader always collects the first line from the first partition on > every csv() call. This is used for schema inference and header filtering. But > if schema is pre-specified by the user and header is false, there's no point. > For certain cases CSV dataset generation is expensive and slow, and this > clogs up the entire executor with 1 job to grab 1 line. If it's not needed, > skipping the first line step is a free lunch for runtime and efficiency. -- This message was sent by Atlassian JIRA (v7.6.3#76005) --------------------------------------------------------------------- To unsubscribe, e-mail: issues-unsubscr...@spark.apache.org For additional commands, e-mail: issues-h...@spark.apache.org