[jira] [Created] (CALCITE-3143) Dividing NULLIF clause may cause Division by zero error

["Li Xian (JIRA)" <ji...@apache.org>]

Li Xian created CALCITE-3143:
--------------------------------

             Summary: Dividing NULLIF clause may cause Division by zero error
                 Key: CALCITE-3143
                 URL: https://issues.apache.org/jira/browse/CALCITE-3143
             Project: Calcite
          Issue Type: Bug
    Affects Versions: 1.16.0
            Reporter: Li Xian


execution of query with pattern like below (column COL_A with type BigDecimal) 
{code:java}
select case when a < 77 and a > 0 then 99 else 88 end from
(
  select SUM(COL_A) / nullif(SUM(0),0) as a
  from SOME_TABLE group by COL_B
)
{code}
 

will cause error java.lang.ArithmeticException: Division by zero.

And the generated code is like below. Division is executed on _input2 (which is 0)
{code:java}
/* 154 */ public Object current() {
/* 155 */ final Object[] current = (Object[]) inputEnumerator.current();
/* 156 */ final java.math.BigDecimal inp1_ = current[1] == null ? (java.math.BigDecimal) null : org.apache.calcite.runtime.SqlFunctions.toBigDecimal(current[1]);
/* 157 */ final int inp2_ = org.apache.calcite.runtime.SqlFunctions.toInt(current[2]);
/* 158 */ final boolean v0 = inp2_ != 0;
/* 159 */ final java.math.BigDecimal v2 = org.apache.calcite.runtime.SqlFunctions.divide(inp1_, new java.math.BigDecimal(
/* 160 */ inp2_));
/* 161 */ return new Object[] {
/* 162 */ inp1_ != null && v0 && org.apache.calcite.runtime.SqlFunctions.lt(v2, $L4J$C$new_java_math_BigDecimal_77_) && (inp1_ != null && v0 && org.apache.calcite.runtime.SqlFunctions.gt(v2, $L4J$C$new_java_math_BigDecimal_0_)) ? 99 : 88,
/* 163 */ current[2]};
/* 164 */ }
{code}
 

 

And by tracing the code generation, I found that in org.apache.calcite.adapter.enumerable.RexImpTable#implementNullSemantics
{code:java}
case FALSE:
  // v0 != null && v1 != null && f(v0, v1)
  for (Ord<RexNode> operand : Ord.zip(call.getOperands())) {
    if (translator.isNullable(operand.e)) {
      list.add(
          translator.translate(
              operand.e, NullAs.IS_NOT_NULL));
      translator = translator.setNullable(operand.e, false);
    }
  }
  list.add(implementCall(translator, call, implementor, nullAs));
  return Expressions.foldAnd(list);
{code}
operand SUM(COL_A) / nullif(SUM(0),0) is set as nullable=false and caused this error. After comment out the below line
{code:java}
translator = translator.setNullable(operand.e, false);{code}
the query will work. May I ask if it is ok to comment out that line? cause this looks like solving my problem temporarily. 

 



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