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https://issues.apache.org/jira/browse/PHOENIX-3591?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15824490#comment-15824490
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Mujtaba Chohan commented on PHOENIX-3591:
-----------------------------------------
Few more details on this. This is with 5K dense columns and using column names
that would be the first and last columns for both immutable encoded and
non-encoded scheme. Generated 20K rows so data fits in OS page cache when
executing query multiple times.
Query
{noformat}
select /*+ SERIAL NO_CACHE*/ ZZZLAST,A00FIRST,sum(k1) from $T group by
ZZZLAST,A00FIRST
{noformat}
Query time for immutable encoded is 13.2sec vs 4.0 seconds for immutable
non-encoded.
> Group by is slower for immutable encoded table
> ----------------------------------------------
>
> Key: PHOENIX-3591
> URL: https://issues.apache.org/jira/browse/PHOENIX-3591
> Project: Phoenix
> Issue Type: Sub-task
> Reporter: Mujtaba Chohan
> Assignee: Samarth Jain
>
> {noformat}
> select /*+ SERIAL NO_CACHE*/ c0,sum(k1) from $T group by c0
> {noformat}
> This is >2X slower when compared to non-encoded table. There are 100 distinct
> values in c0 column.
> For data and schema see data generator script in
> https://issues.apache.org/jira/browse/PHOENIX-3560
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