[CALCITE-5178] Scalar subquery in scalar subquery generates plan that will not compile

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 1.32.0
• Labels: pull-request-available
• Assignee: Benchao Li
• Reporter: Julian Hyde
• Created: 02/Jun/22 22:57
• Updated: 04/Aug/22 00:52
• Resolved: 04/Aug/22 00:52

Description

Scalar subquery in scalar subquery generates plan that will not compile. Example:

> select (select (1, 2));
Error: Error while executing SQL "select (select (1, 2))": Error while compiling generated Java code:
  ...

  public static class Record2_3 implements java.io.Serializable {
    public boolean f0;
    public Object[] f1;
    ...
  }

    java.util.List accumulatorAdders = new java.util.LinkedList();
    accumulatorAdders.add(new org.apache.calcite.linq4j.function.Function2() {
                            public Record2_3 apply(Record2_3 acc, Record2_1 in) {
                              if (acc.f0) {
                                throw new IllegalStateException(
                                    "more than one value in agg SINGLE_VALUE");
                              }
                              acc.f0 = true;
                              acc.f1 = in;
                              return acc;
                            }
                            public Record2_3 apply(Object acc, Object in) {
                              return apply(
                                  (Record2_3) acc,
                                  (Record2_1) in);
                            }
                          }
    );
    ...

Note the line acc.f1 = in; is attempting to assign a Record2_1 value to a Object[] field.

Issue Links

• links to: GitHub Pull Request #2843