GitHub user comnetwork opened a pull request:
https://github.com/apache/phoenix/pull/320
PHOENIX-4820
This patch is mainly for:
1.Isolate the changes made for QueryCompiler to OrderByCompiler.
2.Check more Expression besides ComparisonExpression for
IsColumnConstantExpressionVisitor, add tests for InListExpression ,
CorceExpression and RVC.
3. I think ExpressionUtil.isConstant(Expression) is not suitable for
OrderPreservingTracker.IsConstantVisitor, isStateless() is to check if the
expression is depend on the server state, even for RowKeyColumnExpression ,
isStateless() is false. What we want to check is if a expression is constant
when all children of it are constants, just consider following sql:
select a.ak3 from
(select rand() ak1,length(pk2) ak2,length(pk3) ak3,length(v1)
av1,length(v2) av2 from test order by pk2,pk3 limit 10) a
where a.ak1 = 0.0 and a.av2 = length(substr('abc',1,1))
group by a.ak3,CASE WHEN coalesce(a.ak1,1) > coalesce(a.av2,2) THEN
coalesce(a.ak1,1) ELSE coalesce(a.av2,2) END,a.av1
order by a.ak3,a.av1
Obviously , because of rand(), the Determinism of expression a.ak1 is
Determinism.PER_INVOCATION, so for expression "CASE WHEN coalesce(a.ak1,1) >
coalesce(a.av2,2) THEN coalesce(a.ak1,1) ELSE coalesce(a.av2,2) END", the
determinism is Determinism.PER_INVOCATION and isStateless is false , but
because the a.ak1 and a.av2 are both constants in where clause of outer query,
we can regard "CASE WHEN coalesce(a.ak1,1) > coalesce(a.av2,2) THEN
coalesce(a.ak1,1) ELSE coalesce(a.av2,2) END" as constant in IsConstantVisitor.
You can merge this pull request into a Git repository by running:
$ git pull https://github.com/comnetwork/phoenix 4.x-HBase-1.3
Alternatively you can review and apply these changes as the patch at:
https://github.com/apache/phoenix/pull/320.patch
To close this pull request, make a commit to your master/trunk branch
with (at least) the following in the commit message:
This closes #320
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commit ae0e6ef4dded2c3a8c3d6fffa200acbe971688f8
Author: chenglei <chenglei@...>
Date: 2018-07-31T04:34:25Z
PHOENIX-4820 v2
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