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From "Maryann Xue (JIRA)" <j...@apache.org>
Subject [jira] [Commented] (PHOENIX-4508) Wrong query plan generation
Date Fri, 05 Jan 2018 23:13:00 GMT

    [ https://issues.apache.org/jira/browse/PHOENIX-4508?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16314097#comment-16314097
] 

Maryann Xue commented on PHOENIX-4508:
--------------------------------------

It is important because a table is ordered on its primary key and should not be sorted over
it in the query plan. I guess LID is LOCALID. If that's correct, there is a bug with sort
merge join. I'll look into it.

> Wrong query plan generation
> ---------------------------
>
>                 Key: PHOENIX-4508
>                 URL: https://issues.apache.org/jira/browse/PHOENIX-4508
>             Project: Phoenix
>          Issue Type: Bug
>    Affects Versions: 4.13.2
>            Reporter: Flavio Pompermaier
>              Labels: planner, query
>
> In my Phoenix tables I found that one query ens successfully while another one, logically
equal, does not (unless that I don't apply some tuning to timeouts).
> The 2 queries extract the same data but, while the first query terminates the second
does not.
> PS:  without the USE_SORT_MERGE_JOIN both queries weren't working
> ----
> h2. First query
> {code:sql}
> SELECT /*+ USE_SORT_MERGE_JOIN */ COUNT(*) 
> FROM PEOPLE ds JOIN MYTABLE l ON ds.PERSON_ID = l.LOCALID
> WHERE l.EID IS NULL AND l.DSID = 'PEOPLE' AND l.HAS_CANDIDATES = FALSE;
> {code}
> +---------------------------------------------------------------------------------------------------------------+-----------------+----------------+----------------+
> |                                                     PLAN                          
                           | EST_BYTES_READ  | EST_ROWS_READ  |  EST_INFO_TS   |
> +---------------------------------------------------------------------------------------------------------------+-----------------+----------------+----------------+
> | SORT-MERGE-JOIN (INNER) TABLES                                                    
                           | 14155777900     | 12077867       | 1513754378759  |
> |     CLIENT 42-CHUNK 6168903 ROWS 11324622221 BYTES PARALLEL 3-WAY FULL SCAN OVER PEOPLE
                | 14155777900     | 12077867       | 1513754378759  |
> |         SERVER FILTER BY FIRST KEY ONLY                                           
                           | 14155777900     | 12077867       | 1513754378759  |
> |     CLIENT MERGE SORT                                                             
                           | 14155777900     | 12077867       | 1513754378759  |
> | AND (SKIP MERGE)                                                                  
                           | 14155777900     | 12077867       | 1513754378759  |
> |     CLIENT 15-CHUNK 5908964 ROWS 2831155679 BYTES PARALLEL 15-WAY RANGE SCAN OVER MYTABLE
[0] - [2]  | 14155777900     | 12077867       | 1513754378759  |
> |         SERVER FILTER BY (EID IS NULL AND DSID = 'PEOPLE' AND HAS_CANDIDATES = false)
                  | 14155777900     | 12077867       | 1513754378759  |
> |         SERVER SORTED BY [L.LOCALID]                                              
                               | 14155777900     | 12077867       | 1513754378759  |
> |     CLIENT MERGE SORT                                                             
                           | 14155777900     | 12077867       | 1513754378759  |
> | CLIENT AGGREGATE INTO SINGLE ROW                                                  
                           | 14155777900     | 12077867       | 1513754378759  |
> +---------------------------------------------------------------------------------------------------------------+-----------------+----------------+----------------+
> 10 rows selected (0.041 seconds)
> ----
> h2. Second query
> {code:sql}
> SELECT /*+ USE_SORT_MERGE_JOIN */ COUNT(*) 
> FROM (SELECT LOCALID FROM MYTABLE
> WHERE EID IS NULL AND DSID = 'PEOPLE' AND HAS_CANDIDATES = FALSE) l JOIN PEOPLE  ds ON
ds.PERSON_ID = l.LOCALID;
> {code}
> +--------------------------------------------------------------------------------------------------------------+-----------------+----------------+----------------+
> |                                                     PLAN                          
                          | EST_BYTES_READ  | EST_ROWS_READ  |  EST_INFO_TS   |
> +--------------------------------------------------------------------------------------------------------------+-----------------+----------------+----------------+
> | SORT-MERGE-JOIN (INNER) TABLES                                                    
                          | 14155777900     | 12077867       | 1513754378759  |
> |     CLIENT 15-CHUNK 5908964 ROWS 2831155679 BYTES PARALLEL 3-WAY RANGE SCAN OVER MYTABLE
[0] - [2]  | 14155777900     | 12077867       | 1513754378759  |
> |         SERVER FILTER BY (EID IS NULL AND DSID = 'PEOPLE' AND HAS_CANDIDATES = false)
                 | 14155777900     | 12077867       | 1513754378759  |
> |     CLIENT MERGE SORT                                                             
                          | 14155777900     | 12077867       | 1513754378759  |
> | AND (SKIP MERGE)                                                                  
                          | 14155777900     | 12077867       | 1513754378759  |
> |     CLIENT 42-CHUNK 6168903 ROWS 11324622221 BYTES PARALLEL 42-WAY FULL SCAN OVER PEOPLE
              | 14155777900     | 12077867       | 1513754378759  |
> |         SERVER FILTER BY FIRST KEY ONLY                                           
                          | 14155777900     | 12077867       | 1513754378759  |
> |         SERVER SORTED BY [DS.PERSON_ID]                                           
                        | 14155777900     | 12077867       | 1513754378759  |
> |     CLIENT MERGE SORT                                                             
                          | 14155777900     | 12077867       | 1513754378759  |
> | CLIENT AGGREGATE INTO SINGLE ROW                                                  
                          | 14155777900     | 12077867       | 1513754378759  |
> +--------------------------------------------------------------------------------------------------------------+-----------------+----------------+----------------+



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