You are viewing a plain text version of this content. The canonical link for it is here.
Posted to issues@calcite.apache.org by "Julian Hyde (JIRA)" <ji...@apache.org> on 2018/10/22 22:37:00 UTC

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

    [ https://issues.apache.org/jira/browse/CALCITE-2635?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16659771#comment-16659771 ] 

Julian Hyde edited comment on CALCITE-2635 at 10/22/18 10:36 PM:
-----------------------------------------------------------------

bq. Any suggestions on what file is appropriate for that test?

If you meant database file, I wouldn't use a database file, just a mock.

If you meant java file, SqlToRelConverterTest.java will probably work. I notice that MockRelOptSchema.getTableForMember calls deduceMonotonicity which calls SqlValidatorTable.getMonotonicity, so the bug will surely show up.


was (Author: julianhyde):
bq. 
Any suggestions on what file is appropriate for that test?

If you meant database file, I wouldn't use a database file, just a mock.

If you meant java file, SqlToRelConverterTest.java will probably work. I notice that MockRelOptSchema.getTableForMember calls deduceMonotonicity which calls SqlValidatorTable.getMonotonicity, so the bug will surely show up.

> 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.



--
This message was sent by Atlassian JIRA
(v7.6.3#76005)