[
https://issues.apache.org/jira/browse/DRILL-8083?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17462838#comment-17462838
]
Paul Rogers commented on DRILL-8083:
------------------------------------
[~luoc] , I should think this would be a good newbie bug: the change is
probably isolated to this one plugin. There is probably some issue with how the
Drill schema and log parser are glued together.
> HttpdLogBatchReader creates unnecessary empty maps
> --------------------------------------------------
>
> Key: DRILL-8083
> URL: https://issues.apache.org/jira/browse/DRILL-8083
> Project: Apache Drill
> Issue Type: Bug
> Affects Versions: 1.19.0
> Reporter: Paul Rogers
> Priority: Minor
>
> Run the {{TestHTTPDLogReader.testStarRowSet}} test. Set a breakpoint in
> {{MapWriter.SingleMapWriter.endWrite}}. Step into the {{super.endWrite()}}
> method which will walk the set of child fields. Notice that there are none
> for any of the several map fields.
> One can see that empty maps are expected in the
> {{TestHTTPDLogReader.expectedAllFieldsSchema()}} method.
> Maps (i.e. tuples) are not well defined in SQL. Although Drill makes great
> efforts to support them, an empty tuple is not well defined even in Drill:
> there is nothing one can do with such fields.
> Suggestion: don't create a map field if there are to be no members of the
> map.
> Affected maps:
> * {{request_firstline_original_uri_query_$}}
> * {{request_firstline_uri_query_$}}
> * {{request_referer_last_query_$}}
> * {{request_referer_query_$}}
--
This message was sent by Atlassian Jira
(v8.20.1#820001)
