[jira] [Commented] (ORC-373) If "orc.dictionary.key.threshold" is set to 0, don't try dictionary encoding.

["Sergey Shelukhin (JIRA)" <ji...@apache.org>]

    [ https://issues.apache.org/jira/browse/ORC-373?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16502309#comment-16502309 ] 

Sergey Shelukhin commented on ORC-373:
--------------------------------------

Hmm, I could swear LLAP IO text re-encoding was disabling dictionary encoding for perf reasons for a really long time now.

> If "orc.dictionary.key.threshold" is set to 0, don't try dictionary encoding.
> -----------------------------------------------------------------------------
>
>                 Key: ORC-373
>                 URL: https://issues.apache.org/jira/browse/ORC-373
>             Project: ORC
>          Issue Type: Bug
>    Affects Versions: 1.5.2
>            Reporter: Prasanth Jayachandran
>            Assignee: Prasanth Jayachandran
>            Priority: Major
>             Fix For: 1.5.2, 1.6.0
>
>
> Currently dictionary check happens after creation of first row group entry. Even when row indexes are disabled, rows end up in red-black tree first before getting flushed during write stripe (into direct stream).
> If dictionary threshold is set to <= 0.0 disable dictionary, we should write directly to stream instead of RBTree. This is useful for hive streaming ingest where delta files explicitly disables dictionaries. 



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