[jira] [Commented] (CALCITE-2635) getMonotonocity is slow on wide tables

["Julian Hyde (JIRA)" <ji...@apache.org>]

    [ https://issues.apache.org/jira/browse/CALCITE-2635?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16658055#comment-16658055 ] 

Julian Hyde commented on CALCITE-2635:
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I love cases like this. Perfect opportunity to add a test - mock a table with 20000 columns, prepare a query on it, and make sure performance is ok. 

> getMonotonocity is slow on wide tables
> --------------------------------------
>
>                 Key: CALCITE-2635
>                 URL: https://issues.apache.org/jira/browse/CALCITE-2635
>             Project: Calcite
>          Issue Type: Improvement
>          Components: core
>            Reporter: Gian Merlino
>            Assignee: Gian Merlino
>            Priority: Major
>              Labels: performance
>
> RelOptTableImpl's getMonotonocity does an indexOf on {{rowType.getFieldNames()}}, which is O(N) in the number of fields. IdentifierNamespace calls getMonotonicity once for every field in the table namespace, so it becomes O(N^2) in the number of fields. We observed 2-4 second query planning times with a table that had 18,000 columns, reduced to about 150ms after patching getMonotonicity to be O(1) in the number of fields.



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