Spark: Fix Alignment of Merge Commands with Mixed Case (#4848) (#4874)

* Spark: Fix Alignment of Merge Commands with Mixed Case

Prior to this a mixed-case insert statement would fail to be marked
as aligned after our alignment rule was applied. This would then fail the
entire MERGE INTO command. The commands were correctly aligned but
our alignment check was always case sensitive.

Author: RussellSpitzer

spark/v3.2/spark-extensions/src/main/scala/org/apache/iceberg/spark/extensions/IcebergSparkSessionExtensions.scala

@@ -20,6 +20,7 @@
 package org.apache.iceberg.spark.extensions
 
 import org.apache.spark.sql.SparkSessionExtensions
+import org.apache.spark.sql.catalyst.analysis.AlignedRowLevelIcebergCommandCheck
 import org.apache.spark.sql.catalyst.analysis.AlignRowLevelCommandAssignments
 import org.apache.spark.sql.catalyst.analysis.CheckMergeIntoTableConditions
 import org.apache.spark.sql.catalyst.analysis.MergeIntoIcebergTableResolutionCheck
@@ -55,6 +56,7 @@ class IcebergSparkSessionExtensions extends (SparkSessionExtensions => Unit) {
     extensions.injectResolutionRule { _ => RewriteUpdateTable }
     extensions.injectResolutionRule { _ => RewriteMergeIntoTable }
     extensions.injectCheckRule { _ => MergeIntoIcebergTableResolutionCheck }
+    extensions.injectCheckRule { _ => AlignedRowLevelIcebergCommandCheck }
 
     // optimizer extensions
     extensions.injectOptimizerRule { _ => ExtendedSimplifyConditionalsInPredicate }

spark/v3.2/spark-extensions/src/main/scala/org/apache/spark/sql/catalyst/analysis/AlignedRowLevelIcebergCommandCheck.scala

@@ -0,0 +1,38 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+package org.apache.spark.sql.catalyst.analysis
+
+import org.apache.spark.sql.AnalysisException
+import org.apache.spark.sql.catalyst.plans.logical.LogicalPlan
+import org.apache.spark.sql.catalyst.plans.logical.MergeIntoIcebergTable
+import org.apache.spark.sql.catalyst.plans.logical.UpdateIcebergTable
+
+object AlignedRowLevelIcebergCommandCheck extends (LogicalPlan => Unit) {
+
+  override def apply(plan: LogicalPlan): Unit = {
+    plan foreach {
+      case m: MergeIntoIcebergTable if !m.aligned =>
+        throw new AnalysisException(s"Could not align Iceberg MERGE INTO: $m")
+      case u: UpdateIcebergTable if !u.aligned =>
+        throw new AnalysisException(s"Could not align Iceberg UPDATE: $u")
+      case _ => // OK
+    }
+  }
+}

spark/v3.2/spark-extensions/src/main/scala/org/apache/spark/sql/catalyst/expressions/AssignmentUtils.scala

@@ -40,7 +40,10 @@ object AssignmentUtils extends SQLConfHelper {
     sameSize && table.output.zip(assignments).forall { case (attr, assignment) =>
       val key = assignment.key
       val value = assignment.value
-      toAssignmentRef(attr) == toAssignmentRef(key) &&
+      val refsEqual = toAssignmentRef(attr).zip(toAssignmentRef(key))
+        .forall{ case (attrRef, keyRef) => conf.resolver(attrRef, keyRef)}
+
+      refsEqual &&
         DataType.equalsIgnoreCompatibleNullability(value.dataType, attr.dataType) &&
         (attr.nullable || !value.nullable)
     }

spark/v3.2/spark-extensions/src/test/java/org/apache/iceberg/spark/extensions/TestMerge.java

@@ -1189,6 +1189,36 @@ public void testMergeAlignsUpdateAndInsertActions() {
         sql("SELECT * FROM %s ORDER BY id", tableName));
   }
 
+  @Test
+  public void testMergeMixedCaseAlignsUpdateAndInsertActions() {
+    createAndInitTable("id INT, a INT, b STRING", "{ \"id\": 1, \"a\": 2, \"b\": \"str\" }");
+    createOrReplaceView(
+        "source",
+        "{ \"id\": 1, \"c1\": -2, \"c2\": \"new_str_1\" }\n" +
+        "{ \"id\": 2, \"c1\": -20, \"c2\": \"new_str_2\" }");
+
+    sql("MERGE INTO %s t USING source " +
+        "ON t.iD == source.Id " +
+        "WHEN MATCHED THEN " +
+        "  UPDATE SET B = c2, A = c1, t.Id = source.ID " +
+        "WHEN NOT MATCHED THEN " +
+        "  INSERT (b, A, iD) VALUES (c2, c1, id)", tableName);
+
+    assertEquals(
+        "Output should match",
+        ImmutableList.of(row(1, -2, "new_str_1"), row(2, -20, "new_str_2")),
+        sql("SELECT * FROM %s ORDER BY id", tableName));
+
+    assertEquals(
+        "Output should match",
+        ImmutableList.of(row(1, -2, "new_str_1")),
+        sql("SELECT * FROM %s WHERE id = 1 ORDER BY id", tableName));
+    assertEquals(
+        "Output should match",
+        ImmutableList.of(row(2, -20, "new_str_2")),
+        sql("SELECT * FROM %s WHERE b = 'new_str_2'ORDER BY id", tableName));
+  }
+
   @Test
   public void testMergeUpdatesNestedStructFields() {
     createAndInitTable("id INT, s STRUCT<c1:INT,c2:STRUCT<a:ARRAY<INT>,m:MAP<STRING, STRING>>>",