[CALCITE-1295] ReduceExpressionRule should not reduce AS operator

• Type: Bug
• Status: Closed
• Priority: Minor
• Resolution: Invalid
• Affects Version/s: 1.8.0
• Fix Version/s: 1.9.0
• Component/s: core
• Flags: Patch
• Assignee: Julian Hyde
• Reporter: Jark Wu
• Created: 16/Jun/16 14:51
• Updated: 09/Dec/17 18:37
• Resolved: 07/Jul/16 20:56

Description

In extremely rare cases, if we build relation tree ourselves through RelBuilder.

relBuilder.push(
        LogicalProject.create(relBuilder.peek(),
          Lists.newArrayList(relBuilder.alias(relBuilder.literal(true), "_c0")),
          Lists.newArrayList("_c0")))

Then we may have AS(true, $1) in the expressions, and AS(true, $1) can satisfy ReduceExpressionRule, but AS call do not exist in RexImpTable.INSTANCE, so it throws this :

java.lang.RuntimeException: cannot translate call AS($t0, $t1)
	at org.apache.calcite.adapter.enumerable.RexToLixTranslator.translateCall(RexToLixTranslator.java:533)
	at org.apache.calcite.adapter.enumerable.RexToLixTranslator.translate0(RexToLixTranslator.java:507)
	at org.apache.calcite.adapter.enumerable.RexToLixTranslator.translate(RexToLixTranslator.java:219)
	at org.apache.calcite.adapter.enumerable.RexToLixTranslator.translate0(RexToLixTranslator.java:472)
	at org.apache.calcite.adapter.enumerable.RexToLixTranslator.translate(RexToLixTranslator.java:219)
	at org.apache.calcite.adapter.enumerable.RexToLixTranslator.translate(RexToLixTranslator.java:214)
	at org.apache.calcite.adapter.enumerable.RexToLixTranslator.translateList(RexToLixTranslator.java:700)
	at org.apache.calcite.adapter.enumerable.RexToLixTranslator.translateProjects(RexToLixTranslator.java:189)
	at org.apache.calcite.rex.RexExecutorImpl.compile(RexExecutorImpl.java:80)
	at org.apache.calcite.rex.RexExecutorImpl.compile(RexExecutorImpl.java:59)
	at org.apache.calcite.rex.RexExecutorImpl.reduce(RexExecutorImpl.java:118)
	at org.apache.calcite.rel.rules.ReduceExpressionsRule.reduceExpressionsInternal(ReduceExpressionsRule.java:544)
	at org.apache.calcite.rel.rules.ReduceExpressionsRule.reduceExpressions(ReduceExpressionsRule.java:455)
	at org.apache.calcite.rel.rules.ReduceExpressionsRule.reduceExpressions(ReduceExpressionsRule.java:438)
{

}