IMPALA-14405 ADDENDUM: Catch exception for bad column names

This commit is a fix on top of IMPALA-14405 for the Calcite
planner. The original commit matches column names from the
expression in the select clause.

For instance, if the query is "select 1 + 1", the label in
impala-shell will be "1 + 1". It accomplished this by
retrieving the string from the SqlNode object through the
MySql dialect.

However, when the expression doesn't succeed in the MySql
dialect, an AssertionError gets thrown, causing the query to
fail. We don't want the query to fail, we just want to go
back to using the Calcite expression, e.g. EXPR$0. This
occurred with this specific query:

"select timestamp_col + interval 3 nanoseconds"

So now the exception is caught and the default label name
is used. Eventually we should try to match what Impala has,
but this is a harder problem to fix.

Change-Id: I6c4d76a25fb2486eb1ef19485bce7888d45d282f
Reviewed-on: http://gerrit.cloudera.org:8080/23665
Reviewed-by: Riza Suminto <riza.suminto@cloudera.com>
Tested-by: Impala Public Jenkins <impala-public-jenkins@cloudera.com>
Reviewed-by: Steve Carlin <scarlin@cloudera.com>

java/calcite-planner/src/main/java/org/apache/impala/calcite/service/CalciteRelNodeConverter.java

@@ -177,12 +177,19 @@ public class CalciteRelNodeConverter implements CompilerStep {
     for (SqlNode selectItem : getSelectList(validatedNode)) {
       String fieldName = SqlValidatorUtil.alias(selectItem, 0);
       if (fieldName.startsWith("EXPR$")) {
+        try {
           // If it's a Calcite generated field name, it will be of the form "EXPR$"
           // We get the actual SQL expression using the toSqlString method. There
           // is no Impala Dialect yet, so using MySql dialect to get the field
           // name. The language chosen is irrelevant because we only are using it
           // to grab the expression as/is to use for the label.
           fieldName = selectItem.toSqlString(MysqlSqlDialect.DEFAULT).getSql();
+        } catch (Error e) {
+          // The MysqlDialect may throw an exception if the column name is not
+          // compatible with Mysql.  So we catch the exception and just use the
+          // EXPR$ column name.
+          LOG.debug("Could not use label for {}, using default.", selectItem);
+        }
       }
       fieldNamesBuilder.add(fieldName.toLowerCase());
     }

testdata/workloads/functional-query/queries/QueryTest/calcite.test

@@ -1122,6 +1122,14 @@ int
 row_regex: .*PlannerType: CalcitePlanner.*
 ====
 ---- QUERY
+# IMPALA-14561: Should not be using MySqlDialect to capture labels
+select timestamp_col + interval 3 milliseconds from functional.alltypestiny;
+---- LABELS
+expr$0
+---- RUNTIME_PROFILE
+row_regex: .*PlannerType: CalcitePlanner.*
+====
+---- QUERY
 select cast('nan' as double), cast('inf' as float);
 ---- RESULTS
 NaN,Inf