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  1. MariaDB Server
  2. MDEV-8741

Equal field propagation leaves some remainders after simplifying WHERE zerofill_column=2010 AND zerofill_column>=2010

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      Description

      This script:

      DROP TABLE IF EXISTS t1;
      CREATE TABLE t1 (a INT ZEROFILL);
      INSERT INTO t1 VALUES (2010),(2020);
      EXPLAIN EXTENDED SELECT * FROM t1 WHERE a=2010 AND a>=2010;
      SHOW WARNINGS;

      returns

      +-------+------+---------------------------------------------------------------------------------------+
      | Level | Code | Message                                                                               |
      +-------+------+---------------------------------------------------------------------------------------+
      | Note  | 1003 | select `test`.`t1`.`a` AS `a` from `test`.`t1` where ((`test`.`t1`.`a` = 2010) and 1) |
      +-------+------+---------------------------------------------------------------------------------------+

      Notice, the a>=2010 part was simplified to constant, but the constant was not removed.

      The same problems is repeatable with the YEAR data type:

      DROP TABLE IF EXISTS t1;
      CREATE TABLE t1 (a YEAR);
      INSERT INTO t1 VALUES (2010),(2020);
      EXPLAIN EXTENDED SELECT * FROM t1 WHERE a=2010 AND a>=2010;
      SHOW WARNINGS;

      If I use "INT" instead of "INT ZEROFILL" or "YEAR", it works as expected:

      DROP TABLE IF EXISTS t1;
      CREATE TABLE t1 (a INT);
      INSERT INTO t1 VALUES (2010),(2020);
      EXPLAIN EXTENDED SELECT * FROM t1 WHERE a=2010 AND a>=2010;
      SHOW WARNINGS;

      returns:

      +-------+------+-------------------------------------------------------------------------------+
      | Level | Code | Message                                                                       |
      +-------+------+-------------------------------------------------------------------------------+
      | Note  | 1003 | select `test`.`t1`.`a` AS `a` from `test`.`t1` where (`test`.`t1`.`a` = 2010) |
      +-------+------+-------------------------------------------------------------------------------+

      as expected.

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              • Assignee:
                bar Alexander Barkov
                Reporter:
                bar Alexander Barkov
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                • Created:
                  Updated:
                  Resolved: