[jira] [Updated] (DRILL-6101) Optimize Implicit Columns Processing

["Pritesh Maker (JIRA)" <ji...@apache.org>]

     [ 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
>  



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