[CALCITE-4579] Piglet throws ClassCastException if Pig Latin script contains FLATTEN or STRSPLIT operators

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 1.27.0
• Component/s: piglet
• Labels: pull-request-available
• Assignee: Julian Hyde
• Reporter: mahesh kumar behera
• Created: 12/Apr/21 02:15
• Updated: 03/Jun/21 22:31
• Resolved: 15/Apr/21 04:15

Description

In the piglet component, while converting a Pig Latin script to SQL, the conversion expects the child to be a SqlIdentifier. But a SqlBasicCall is returned.

Script

A = LOAD 'scott.DEPT' as (DEPTNO:int, DNAME:chararray, LOC:CHARARRAY);
B = FOREACH A GENERATE FLATTEN(STRSPLIT(DNAME, ',')) as NAMES;
 

    java.lang.ClassCastException: org.apache.calcite.sql.SqlBasicCall cannot be cast to org.apache.calcite.sql.SqlIdentifier
        at org.apache.calcite.rel.rel2sql.SqlImplementor$Context.toSql(SqlImplementor.java:720)
        at org.apache.calcite.rel.rel2sql.RelToSqlConverter.visit(RelToSqlConverter.java:351)
        at org.apache.calcite.util.ReflectUtil$2.invoke(ReflectUtil.java:531)
        at org.apache.calcite.rel.rel2sql.RelToSqlConverter.dispatch(RelToSqlConverter.java:134)
        at org.apache.calcite.rel.rel2sql.RelToSqlConverter.visitInput(RelToSqlConverter.java:142)
        at org.apache.calcite.rel.rel2sql.SqlImplementor.visitInput(SqlImplementor.java:185)
        at org.apache.calcite.rel.rel2sql.SqlImplementor.visitInput(SqlImplementor.java:173)
        at org.apache.calcite.rel.rel2sql.SqlImplementor.visitRoot(SqlImplementor.java:153)
        at org.apache.calcite.piglet.PigConverter.pigToSql(PigConverter.java:244)
        at org.apache.calcite.piglet.PigConverter.pigToSql(PigConverter.java:227)
        at org.apache.calcite.test.PigRelOpTest$Fluent.assertSql(PigRelOpTest.java:100)
        at org.apache.calcite.test.PigRelOpTest$Fluent.access$200(PigRelOpTest.java:64)
        at org.apache.calcite.test.PigRelOpTest.testUdf(PigRelOpTest.java:286) 

Issue Links

• is related to: CALCITE-785 Add "Piglet", a subset of Pig Latin on top of Calcite algebra
• links to: GitHub Pull Request #2396