Andrew Ray created SPARK-18457: ---------------------------------- Summary: ORC and other columnar formats using HiveShim read all columns when doing a simple count Key: SPARK-18457 URL: https://issues.apache.org/jira/browse/SPARK-18457 Project: Spark Issue Type: Bug Components: SQL Affects Versions: 2.0.2, 1.6.3 Environment: Hadoop 2.7.0 Reporter: Andrew Ray Priority: Minor
Doing a `select count(*) from a_orc_table` reads all columns and thus is slower than a query selecting one like `select count(a_column) from a_orc_table`. Data read can be seen in the UI (appears to only be accurate for Hadoop 2.5+ based on comment in FileScanRDD.scala line 80). I will create a PR shortly. -- This message was sent by Atlassian JIRA (v6.3.4#6332) --------------------------------------------------------------------- To unsubscribe, e-mail: issues-unsubscr...@spark.apache.org For additional commands, e-mail: issues-h...@spark.apache.org