Set the schema case sensitivity to false for Hive

coral-common/src/main/java/com/linkedin/coral/common/HiveTypeSystem.java

@@ -156,6 +156,11 @@ public boolean shouldConvertRaggedUnionTypesToVarying() {
     return true;
   }
 
+  @Override
+  public boolean isSchemaCaseSensitive() {
+    return false;
+  }
+
   private RelDataType nullableType(RelDataTypeFactory typeFactory, SqlTypeName typeName) {
     return typeFactory.createTypeWithNullability(typeFactory.createSqlType(typeName), true);
   }

coral-hive/src/test/java/com/linkedin/coral/hive/hive2rel/HiveToRelConverterTest.java

@@ -16,6 +16,7 @@
 import org.apache.calcite.plan.RelOptUtil;
 import org.apache.calcite.rel.RelNode;
 import org.apache.calcite.runtime.CalciteContextException;
+import org.apache.calcite.sql.SqlNode;
 import org.apache.calcite.sql.type.ReturnTypes;
 import org.apache.calcite.sql.type.SqlTypeFamily;
 import org.apache.calcite.sql.type.SqlTypeName;
@@ -618,6 +619,20 @@ public void testCastToDecimalDefault() {
     assertEquals(generated, expected);
   }
 
+  @Test
+  public void testNameSakeColumnNamesShouldGetUniqueIdentifiers() {
+    String expected = "SELECT \"some_id\"\n"
+        + "FROM (SELECT \"duplicate_column_name_a\".\"some_id\", \"t\".\"SOME_ID\" AS \"SOME_ID0\"\n"
+        + "FROM \"hive\".\"default\".\"duplicate_column_name_a\"\n"
+        + "LEFT JOIN (SELECT TRIM(\"some_id\") AS \"SOME_ID\", CAST(TRIM(\"some_id\") AS VARCHAR(10485760)) AS \"$f1\"\n"
+        + "FROM \"hive\".\"default\".\"duplicate_column_name_b\") AS \"t\" ON \"duplicate_column_name_a\".\"some_id\" = \"t\".\"$f1\") AS \"t0\"\n"
+        + "WHERE \"t0\".\"some_id\" <> ''";
+    SqlNode node = viewToSqlNode("default", "view_namesake_column_names");
+    converter.getSqlValidator().validate(node);
+    String generated = nodeToStr(node);
+    assertEquals(generated, expected);
+  }
+
   private String relToString(String sql) {
     return RelOptUtil.toString(converter.convertSql(sql));
   }

coral-hive/src/test/java/com/linkedin/coral/hive/hive2rel/TestUtils.java

@@ -197,11 +197,19 @@ public static TestHive setupDefaultHive(HiveConf conf) throws IOException {
       driver.run(
           "CREATE TABLE IF NOT EXISTS nested_union(foo uniontype<int, double, struct<a:int, b:uniontype<int, double>>>)");
 
+      driver.run("CREATE TABLE IF NOT EXISTS duplicate_column_name_a (some_id string)");
+      driver.run("CREATE TABLE IF NOT EXISTS duplicate_column_name_b (some_id string)");
+      driver.run("CREATE VIEW IF NOT EXISTS view_namesake_column_names AS\n"
+          + "        SELECT a.some_id FROM duplicate_column_name_a a\n"
+          + "        LEFT JOIN ( SELECT trim(some_id) AS SOME_ID FROM duplicate_column_name_b) b ON a.some_id = b.some_id\n"
+          + "        WHERE a.some_id != ''");
+
       testHive.databases = ImmutableList.of(
           new TestHive.DB("test", ImmutableList.of("tableOne", "tableTwo", "tableOneView")),
           new TestHive.DB("default",
               ImmutableList.of("bar", "complex", "foo", "foo_view", "null_check_view", "null_check_wrapper",
-                  "schema_evolve", "view_schema_evolve", "view_schema_evolve_wrapper", "union_table", "nested_union")),
+                  "schema_evolve", "view_schema_evolve", "view_schema_evolve_wrapper", "union_table", "nested_union",
+                  "duplicate_column_name_a", "duplicate_column_name_b", "view_namesake_column_names")),
           new TestHive.DB("fuzzy_union",
               ImmutableList.of("tableA", "tableB", "tableC", "union_view", "union_view_with_more_than_two_tables",
                   "union_view_with_alias", "union_view_single_branch_evolved",

coral-spark/src/test/java/com/linkedin/coral/spark/CoralSparkTest.java

@@ -727,4 +727,16 @@ public void testDeduplicateUdf() {
     List<SparkUDFInfo> udfJars = coralSpark.getSparkUDFInfoList();
     assertEquals(1, udfJars.size());
   }
+
+  @Test
+  public void testNameSakeColumnNamesShouldGetUniqueIdentifiers() {
+    String targetSql = String.join("\n", "SELECT some_id", "FROM (SELECT tablea.some_id, t.SOME_ID SOME_ID0",
+        "FROM duplicate_column_name.tablea",
+        "LEFT JOIN (SELECT TRIM(some_id) SOME_ID, CAST(TRIM(some_id) AS STRING) $f1",
+        "FROM duplicate_column_name.tableb) t ON tablea.some_id = t.$f1) t0", "WHERE t0.some_id <> ''");
+    RelNode relNode = TestUtils.toRelNode("duplicate_column_name", "view_namesake_column_names");
+    CoralSpark coralSpark = CoralSpark.create(relNode);
+    String expandedSql = coralSpark.getSparkSql();
+    assertEquals(expandedSql, targetSql);
+  }
 }

coral-spark/src/test/java/com/linkedin/coral/spark/TestUtils.java

@@ -73,7 +73,7 @@ public static void initializeViews(HiveConf conf) throws HiveException, MetaExce
 
     run(driver, String.join("\n", "", "CREATE VIEW IF NOT EXISTS foo_view", "AS", "SELECT b AS bcol, sum(c) AS sum_c",
         "FROM foo", "GROUP BY b"));
-    run(driver, "DROP VIEW IF EXITS foo_v1");
+    run(driver, "DROP VIEW IF EXISTS foo_v1");
     run(driver,
         String.join("\n", "", "CREATE VIEW IF NOT EXISTS foo_v1 ", "AS ",
             "SELECT DATE '2013-01-01', '2017-08-22 01:02:03', CAST(123 AS SMALLINT), CAST(123 AS TINYINT) ", "FROM foo",
@@ -114,6 +114,12 @@ public static void initializeViews(HiveConf conf) throws HiveException, MetaExce
     run(driver, String.join("\n", "", "CREATE VIEW IF NOT EXISTS named_struct_view", "AS",
         "SELECT named_struct('abc', 123, 'def', 'xyz') AS named_struc", "FROM bar"));
 
+    run(driver, String.join("\n", "", "CREATE DATABASE IF NOT EXISTS duplicate_column_name"));
+    run(driver, "CREATE TABLE duplicate_column_name.tableA (some_id string)");
+    run(driver, "CREATE TABLE duplicate_column_name.tableB (some_id string)");
+    run(driver, "CREATE VIEW IF NOT EXISTS duplicate_column_name.view_namesake_column_names AS "
+        + "SELECT a.some_id FROM duplicate_column_name.tableA a LEFT JOIN (SELECT trim(some_id) AS SOME_ID FROM duplicate_column_name.tableB) b ON a.some_id = b.some_id WHERE a.some_id != ''");
+
     // Views and tables used in FuzzyUnionViewTest
     run(driver, String.join("\n", "", "CREATE DATABASE IF NOT EXISTS fuzzy_union"));
 

coral-trino/src/test/java/com/linkedin/coral/trino/rel2trino/HiveToTrinoConverterTest.java

@@ -196,7 +196,14 @@ public Object[][] viewTestCasesProvider() {
             + "FROM \"test\".\"table_ints_strings\"" },
 
         { "test", "cast_decimal_view", "SELECT CAST(\"a\" AS DECIMAL(6, 2)) AS \"casted_decimal\"\n"
-            + "FROM \"test\".\"table_ints_strings\"" } };
+            + "FROM \"test\".\"table_ints_strings\"" },
+
+        { "test", "view_namesake_column_names", "SELECT \"some_id\"\n"
+            + "FROM (SELECT \"duplicate_column_name_a\".\"some_id\" AS \"some_id\", \"t\".\"SOME_ID\" AS \"SOME_ID0\"\n"
+            + "FROM \"test\".\"duplicate_column_name_a\"\n"
+            + "LEFT JOIN (SELECT TRIM(\"some_id\") AS \"SOME_ID\", CAST(TRIM(\"some_id\") AS VARCHAR(65536)) AS \"$f1\"\n"
+            + "FROM \"test\".\"duplicate_column_name_b\") AS \"t\" ON \"duplicate_column_name_a\".\"some_id\" = \"t\".\"$f1\") AS \"t0\"\n"
+            + "WHERE \"t0\".\"some_id\" <> ''" } };
   }
 
   @Test

coral-trino/src/test/java/com/linkedin/coral/trino/rel2trino/TestUtils.java

@@ -359,6 +359,11 @@ public static void initializeViews(HiveConf conf) throws HiveException, MetaExce
     run(driver,
         "CREATE VIEW IF NOT EXISTS test.view_with_transform_column_name_reset AS SELECT struct_col AS structCol FROM (SELECT * FROM test.viewA UNION ALL SELECT * FROM test.viewB) X");
     run(driver, "ALTER TABLE test.tableT CHANGE COLUMN structCol structCol struct<a:int, b:string>");
+
+    run(driver, "CREATE TABLE test.duplicate_column_name_a (some_id string)");
+    run(driver, "CREATE TABLE test.duplicate_column_name_b (some_id string)");
+    run(driver, "CREATE VIEW IF NOT EXISTS test.view_namesake_column_names AS \n"
+        + "SELECT a.some_id FROM test.duplicate_column_name_a a LEFT JOIN ( SELECT trim(some_id) AS SOME_ID FROM test.duplicate_column_name_b) b ON a.some_id = b.some_id WHERE a.some_id != ''");
   }
 
   public static RelNode convertView(String db, String view) {