• unknown's avatar
    Fixed bug #21390: wrong estimate of rows after elimination of · f121994d
    unknown authored
    const tables. This resulted in choosing extremely inefficient
    execution plans in same cases when distribution of data in
    joined were skewed (see the customer test case for the bug).
    
    
    
    mysql-test/r/select.result:
      Added a test case for bug #21390: wrong estimate of rows
      after elimination of const tables.
      Includded a test case that checks the code added by the patch
      that handles outer joins with no matches after substitution of
      a const table in an efficient way.
    mysql-test/t/select.test:
      Added a test case for bug #21390: wrong estimate of rows
      after elimination of const tables.
      Included a test case that checks the code added by the patch
      that handles outer joins with no matches after substitution of
      a const table in an efficient way.
    sql/sql_select.cc:
      Fixed bug #21390: wrong estimate of rows after elimination of
      const tables. This resulted in choosing extremely inefficient
      execution plans in same cases when distribution of data in
      joined were skewed (see the customer test case for the bug).
      Also added the code to handle outer joins with no matches after
      substitution of a const table in an efficient way. 
      Corrected calculation of the null rejecting key conditions.
    f121994d
select.result 94.3 KB