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[jira] [Created] (CALCITE-2630) Convert SqlInOperator to a IN-Function


pengzhiwei created CALCITE-2630:
-----------------------------------

             Summary: Convert SqlInOperator to a IN-Function
                 Key: CALCITE-2630
                 URL: https://issues.apache.org/jira/browse/CALCITE-2630
             Project: Calcite
          Issue Type: Improvement
          Components: core
    Affects Versions: 1.17.0
            Reporter: pengzhiwei
            Assignee: Julian Hyde


Currently Calcite translate "IN" to "OR" expression when the count of  IN's operands less than "inSubQueryThreshold" and to "Join" when the count greater  than "inSubQueryThreshold" to get better performance.

  However this translation to "JOIN" is so complex,especially when the "IN" expression located in the "select" or "join on condition".For example:

 
{code:java}
select case when deptno in (1,2) then 0 else 1 end from emp
{code}
the logical plan generated as follow:

 

 
{code:java}
LogicalProject(EXPR$0=[CASE(CAST(CASE(=($9, 0), false, IS NOT NULL($13), true, IS NULL($11), null, <($10, $9), null, false)):BOOLEAN NOT NULL, 0, 1)])
LogicalJoin(condition=[=($11, $12)], joinType=[left])
LogicalProject(EMPNO=[$0], ENAME=[$1], JOB=[$2], MGR=[$3], HIREDATE=[$4], SAL=[$5], COMM=[$6], DEPTNO=[$7], SLACKER=[$8], $f0=[$9], $f1=[$10], DEPTNO0=[$7])
LogicalJoin(condition=[true], joinType=[inner])
LogicalTableScan(table=[[CATALOG, SALES, EMP]])
LogicalAggregate(group=[{}], agg#0=[COUNT()], agg#1=[COUNT($0)])
LogicalProject(ROW_VALUE=[$0], $f1=[true])
LogicalValues(tuples=[[{ 1 }, { 2 }]])
LogicalAggregate(group=[{0}], agg#0=[MIN($1)])
LogicalProject(ROW_VALUE=[$0], $f1=[true])
LogicalValues(tuples=[[{ 1 }, { 2 }]])

{code}
The generated logical plan is so complex for such a simple sql!

 

I think we can treat "IN" as a function like "plus" and "minus".And there is no translation spending on "IN" just keep it as it is.This would be much clear in the logical plan!

In the compute stage,We can provide a "InExpression":

 
{code:java}
InExpression(left,condition0,condition1,...){code}
 

 We can put all the constant conditions to a "Set".In that way,the computational complexity can reduce from O(n) to O(1).

It would be much clear and have a good performance.And we have implement it in our streaming-sql system.

 



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