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  1. Phoenix
  2. PHOENIX-2514

Even with ORDER BY clause the LIMIT does not work correctly with salted tables containing many records.

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    Details

    • Type: Bug
    • Status: Open
    • Priority: Critical
    • Resolution: Unresolved
    • Affects Version/s: 4.5.1
    • Fix Version/s: None
    • Component/s: None
    • Environment:

      HBase-0.98.14

    • Flags:
      Patch, Important

      Description

      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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          Sumit Nigam

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            • Assignee:
              Unassigned
              Reporter:
              sumit.nigam Sumit Nigam
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              Dates

              • Created:
                Updated: