[jira] [Commented] (PHOENIX-2514) Even with ORDER BY clause the LIMIT does not work correctly with salted tables containing many records.

["James Taylor (JIRA)" <ji...@apache.org>]

    [ https://issues.apache.org/jira/browse/PHOENIX-2514?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15113930#comment-15113930 ] 

James Taylor commented on PHOENIX-2514:
---------------------------------------

[~sumit.nigam] - any luck reproducing this? 

> Even with ORDER BY clause the LIMIT does not work correctly with salted tables containing many records.
> -------------------------------------------------------------------------------------------------------
>
>                 Key: PHOENIX-2514
>                 URL: https://issues.apache.org/jira/browse/PHOENIX-2514
>             Project: Phoenix
>          Issue Type: Bug
>    Affects Versions: 4.5.1
>         Environment: HBase-0.98.14
>            Reporter: Sumit Nigam
>            Priority: Critical
>              Labels: LIMIT, hbase, phoenix, salted
>         Attachments: data.zip
>
>
> A query such as SELECT CURRENT_TIMESTAMP FROM TBL ORDER BY CURRENT_TIMESTAMP DESC LIMIT 1 does not really return the MAX(CURRENT_TIMESTAMP). The table is salted and has 200272 records.
> select current_timestamp from TBL order by current_timestamp desc limit 1;
> +------------------------------------------+
> |            CURRENT_TIMESTAMP    |
> +------------------------------------------+
> | 1448815328556                            |
> +------------------------------------------+
> select max(current_timestamp) from TBL;
> +------------------------------------------+
> |         MAX("CURRENT_TIMESTAMP")         |
> +------------------------------------------+
> | 1449732792090                            |
> +------------------------------------------+
> The results are different. MAX is of course, returning the right record.
> The above query is one example. There are other queries which also seem to be returning incorrect record with ORDER BY and LIMIT.
> Is this also correct that when there is a WHERE clause limiting the number of projected records, then LIMIT seems to work fine? I seem to be noticing that also.
> The table DDL is:
> CREATE TABLE IF NOT EXISTS TBL 
> (CURRENT_TIMESTAMP BIGINT NOT NULL, ID VARCHAR(96), CURR_EXDOC VARCHAR,  CURR_CHECKSUM VARCHAR(32), SUMMARY VARCHAR, 
> CONSTRAINT PK PRIMARY KEY(CURRENT_TIMESTAMP, ID)) 
> BLOCKCACHE=FALSE, COMPRESSION=SNAPPY, SALT_BUCKETS=8



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