[Fix](Nereids) fix column statistic derive in outer join estimation#25586
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…25586) Problem: When join estimation, upper join output slot statistic ndv would go wrong Example: we have two table: tableA (a1[ndv = 10.0]) tableB(b1[ndv = 0.0], b2[ndv = 10.0]) tableA left join tableB on A.a1 = B.b1. which B.b1 with ndv zero. the problem is after join estimation, B.b2 changed to 1.0. Reason: When estimating outer join, we can assume it behave like inner join. But we estimation then like inner join do Solved: When estimation outer join, output slot would update seperatly.
…pache#25586) Problem: When join estimation, upper join output slot statistic ndv would go wrong Example: we have two table: tableA (a1[ndv = 10.0]) tableB(b1[ndv = 0.0], b2[ndv = 10.0]) tableA left join tableB on A.a1 = B.b1. which B.b1 with ndv zero. the problem is after join estimation, B.b2 changed to 1.0. Reason: When estimating outer join, we can assume it behave like inner join. But we estimation then like inner join do Solved: When estimation outer join, output slot would update seperatly.
…pache#25586) Problem: When join estimation, upper join output slot statistic ndv would go wrong Example: we have two table: tableA (a1[ndv = 10.0]) tableB(b1[ndv = 0.0], b2[ndv = 10.0]) tableA left join tableB on A.a1 = B.b1. which B.b1 with ndv zero. the problem is after join estimation, B.b2 changed to 1.0. Reason: When estimating outer join, we can assume it behave like inner join. But we estimation then like inner join do Solved: When estimation outer join, output slot would update seperatly.
…pache#25586) Problem: When join estimation, upper join output slot statistic ndv would go wrong Example: we have two table: tableA (a1[ndv = 10.0]) tableB(b1[ndv = 0.0], b2[ndv = 10.0]) tableA left join tableB on A.a1 = B.b1. which B.b1 with ndv zero. the problem is after join estimation, B.b2 changed to 1.0. Reason: When estimating outer join, we can assume it behave like inner join. But we estimation then like inner join do Solved: When estimation outer join, output slot would update seperatly.
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Proposed changes
Problem:
When join estimation, upper join output slot statistic ndv would go wrong
Example:
we have two table:
tableA (a1[ndv = 10.0]) tableB(b1[ndv = 0.0], b2[ndv = 10.0])
tableA left join tableB on A.a1 = B.b1. which B.b1 with ndv zero.
the problem is after join estimation, B.b2 changed to 1.0.
Reason:
When estimating outer join, we can assume it behave like inner join. But we estimation then like inner join do
Solved:
When estimation outer join, output slot would update seperatly.
Further comments
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