[jira] [Assigned] (SPARK-26935) Skip DataFrameReader's CSV first line scan when not used
[ https://issues.apache.org/jira/browse/SPARK-26935?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ] Sean Owen reassigned SPARK-26935: - Assignee: Douglas Colkitt > 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 > 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
[jira] [Assigned] (SPARK-26935) Skip DataFrameReader's CSV first line scan when not used
[ https://issues.apache.org/jira/browse/SPARK-26935?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ] Apache Spark reassigned SPARK-26935: Assignee: Apache Spark > 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: Apache Spark >Priority: Minor > Labels: easyfix, performance, pull-request-available > 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
[jira] [Assigned] (SPARK-26935) Skip DataFrameReader's CSV first line scan when not used
[ https://issues.apache.org/jira/browse/SPARK-26935?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ] Apache Spark reassigned SPARK-26935: Assignee: (was: Apache Spark) > 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 >Priority: Minor > Labels: easyfix, performance, pull-request-available > 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
