[CALCITE-6353] Optimization CoreRules.PROJECT_REDUCE_EXPRESSIONS crashes while optimizing ARRAY_CONCAT expression

• Type: Bug
• Status: Closed
• Priority: Minor
• Resolution: Fixed
• Affects Version/s: 1.36.0
• Fix Version/s: 1.37.0
• Component/s: core
• Labels: pull-request-available
• Assignee: Unassigned
• Reporter: Mihai Budiu
• Created: 04/Apr/24 20:35
• Updated: 06/May/24 22:19
• Resolved: 09/Apr/24 15:26

Description

The following RelOptRulesTest

 @Test void testArrayConcat() {
    final String sql = "select array_concat(ARRAY [1, 2], ARRAY [3, 4])";
    sql(sql).withFactory(
            t -> t.withOperatorTable(
                opTab -> SqlLibraryOperatorTableFactory.INSTANCE.getOperatorTable(
                    SqlLibrary.STANDARD, SqlLibrary.BIG_QUERY)))
        .withRule(CoreRules.PROJECT_REDUCE_EXPRESSIONS)
        .check();
  }

crashes with the following stack trace:

java.lang.RuntimeException: While compiling [ARRAY_CONCAT(ARRAY(1, 2), ARRAY(3, 4))]
	at org.apache.calcite.rex.RexExecutable.compile(RexExecutable.java:73)
	at org.apache.calcite.rex.RexExecutable.<init>(RexExecutable.java:53)
	at org.apache.calcite.rex.RexExecutorImpl.reduce(RexExecutorImpl.java:145)
	at org.apache.calcite.rel.rules.ReduceExpressionsRule.reduceExpressionsInternal(ReduceExpressionsRule.java:774)
	at org.apache.calcite.rel.rules.ReduceExpressionsRule.reduceExpressions(ReduceExpressionsRule.java:714)

It seems that the generated code passed to Janino is invalid:

Line 10, Column 5: Assignment conversion not possible from type "java.util.ArrayList" to type "java.lang.Object[]"
org.codehaus.commons.compiler.CompileException: Line 10, Column 5: Assignment conversion not possible from type "java.util.ArrayList" to type "java.lang.Object[]"

Issue Links

• links to: GitHub Pull Request #3751