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From "Vlad Krava (JIRA)" <j...@apache.org>
Subject [jira] [Created] (PHOENIX-5287) incorrect results on COUNT(*) or COUNT(1) with GLOBAL INDEX
Date Fri, 17 May 2019 21:09:00 GMT
Vlad Krava created PHOENIX-5287:
-----------------------------------

             Summary: incorrect results on COUNT(*) or COUNT(1) with GLOBAL INDEX
                 Key: PHOENIX-5287
                 URL: https://issues.apache.org/jira/browse/PHOENIX-5287
             Project: Phoenix
          Issue Type: Bug
    Affects Versions: 5.0.0
         Environment: Environment and data information:
 * Column structure of TABLE_A is fully identical to TABLE_B
 * TABLE_A has a GLOBAL INDEX
 * TABLE_B has a LOCAL INDEX
            Reporter: Vlad Krava


COUNT(*) and COUNT(1) commands display incorrect(outdated) statistics for table with GLOBAL
index.

*Example:*
 * Export TABLE_A to SCV file (SELECT * FROM *POMG.TABLE_A*)
 * Import CSV file to TABLE_B
 * COUNT operation on 'TABLE_A' was constantly returning with an amount of 218623 (for 2 days
without any data modifications!!!) :
 ** 0: *jdbc:phoenix:> select count(1) from POMG.TABLE_A*;
 *** RESULT: 218623
 * Newly exported table from CSV file (TABLE_B) showed different (higher amount of records)
 ** 0: *jdbc:phoenix:> select count(1) from POMG.TABLE_B*;
 *** RESULT: 218683
 * COUNT in Hbase is returning the bigger value than COUNT comparing to Phoenix table ( 218683
vs 218623)
 * Phoenix Statistics for this table was updated few time for the past few testing days
 * I took few attends to define data misalignments by executing diff for primary keys:
 ** select key_1 from *POMG.TABLE_A* where key_1 not in (select key_1 from *POMG.TABLE_B*)
** - 0 records selected (_Doesn't make sense considering a fact that TABLE_A larger than
TABLE_B and key_1 is unique PRIMARY KEY_)
 ** select key_1 from *POMG.TABLE_B* where key_1 not in (select key_1 from *POMG.TABLE_A*)
** - 23 records selected (_Doesn't make sense considering a fact that TABLE_A larger than
TABLE_B and key_1 is unique PRIMARY KEY_)

*Workaround:*
 * **After executing ALTER INDEX with REBUILD flag COUNT statistics for TABLE_A become identical
to TABLE_B
 * Diff selects didn't show any differences between  *POMG.TABLE_A* and  **  *POMG.TABLE_B***

 

 



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