Fix table name parsing for window queries

pinot-common/src/main/java/org/apache/pinot/sql/parsers/CalciteSqlParser.java

@@ -46,6 +46,7 @@
 import org.apache.calcite.sql.SqlSelect;
 import org.apache.calcite.sql.SqlSelectKeyword;
 import org.apache.calcite.sql.SqlSetOption;
+import org.apache.calcite.sql.SqlWindow;
 import org.apache.calcite.sql.fun.SqlBetweenOperator;
 import org.apache.calcite.sql.fun.SqlCase;
 import org.apache.calcite.sql.fun.SqlLikeOperator;
@@ -803,8 +804,14 @@ private static Expression toExpression(SqlNode node) {
         if (node instanceof SqlDataTypeSpec) {
           // This is to handle expression like: CAST(col AS INT)
           return RequestUtils.getLiteralExpression(((SqlDataTypeSpec) node).getTypeName().getSimple());
-        } else {
+        } else if (node instanceof SqlWindow) {
+          // Window definitions appear as operands of OVER calls. PinotQuery does not model window frames directly, but
+          // compiling them as literals keeps parsing/table-name extraction from failing on multi-stage window queries.
+          return RequestUtils.getLiteralExpression(node.toString());
+        } else if (node instanceof SqlBasicCall) {
           return compileFunctionExpression((SqlBasicCall) node);
+        } else {
+          throw new SqlCompilationException("Unsupported sql node - " + node);
         }
     }
   }

pinot-common/src/test/java/org/apache/pinot/common/utils/request/RequestUtilsTest.java

@@ -67,7 +67,10 @@ public Object[][] queryProvider() {
       {"select foo from countries where bar > 1", Set.of("countries")},
       {"select 1", null},
       {"SET useMultiStageEngine=true; SELECT table1.foo, table2.bar FROM "
-              + "table1 JOIN table2 ON table1.id = table2.id LIMIT 10;", Set.of("table1", "table2")}
+              + "table1 JOIN table2 ON table1.id = table2.id LIMIT 10;", Set.of("table1", "table2")},
+      {"SET useMultiStageEngine=true; SELECT foo, occurredAt, "
+              + "LAG(occurredAt) OVER (PARTITION BY foo ORDER BY occurredAt) AS laggedAt FROM events",
+          Set.of("events")}
     };
   }