[ https://issues.apache.org/jira/browse/DRILL-6101?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]
Pritesh Maker updated DRILL-6101: --------------------------------- Fix Version/s: (was: 1.14.0) > Optimize Implicit Columns Processing > ------------------------------------ > > Key: DRILL-6101 > URL: https://issues.apache.org/jira/browse/DRILL-6101 > Project: Apache Drill > Issue Type: Improvement > Components: Execution - Relational Operators > Affects Versions: 1.12.0 > Reporter: salim achouche > Assignee: salim achouche > Priority: Critical > > Problem Description - > * Apache Drill allows users to specify columns even for SELECT STAR queries > * From my discussion with [~paul-rogers], Apache Calcite has a limitation > where the, extra columns are not provided > * The workaround has been to always include all implicit columns for SELECT > STAR queries > * Unfortunately, the current implementation is very inefficient as implicit > column values get duplicated; this leads to substantial performance > degradation when the number of rows are large > Suggested Optimization - > * The NullableVarChar vector should be enhanced to efficiently store > duplicate values > * This will not only address the current Calcite limitations (for SELECT > STAR queries) but also optimize all queries with implicit columns > -- This message was sent by Atlassian JIRA (v7.6.3#76005)