From f817412f45abaefd5a57996c2a9dc11b9b34071b Mon Sep 17 00:00:00 2001
From: Kevin Ge <kge@linkedin.com>
Date: Wed, 24 Jul 2024 15:07:20 -0400
Subject: [PATCH] rename (#518)

---
 ...onvertletTable.java => CoralConvertletTable.java} | 12 +++++++-----
 .../coral/hive/hive2rel/HiveToRelConverter.java      |  2 +-
 .../coral/trino/trino2rel/TrinoToRelConverter.java   |  6 +++---
 3 files changed, 11 insertions(+), 9 deletions(-)
 rename coral-hive/src/main/java/com/linkedin/coral/hive/hive2rel/{HiveConvertletTable.java => CoralConvertletTable.java} (79%)

diff --git a/coral-hive/src/main/java/com/linkedin/coral/hive/hive2rel/HiveConvertletTable.java b/coral-hive/src/main/java/com/linkedin/coral/hive/hive2rel/CoralConvertletTable.java
similarity index 79%
rename from coral-hive/src/main/java/com/linkedin/coral/hive/hive2rel/HiveConvertletTable.java
rename to coral-hive/src/main/java/com/linkedin/coral/hive/hive2rel/CoralConvertletTable.java
index 5b82a8595..774e81d0f 100644
--- a/coral-hive/src/main/java/com/linkedin/coral/hive/hive2rel/HiveConvertletTable.java
+++ b/coral-hive/src/main/java/com/linkedin/coral/hive/hive2rel/CoralConvertletTable.java
@@ -1,5 +1,5 @@
 /**
- * Copyright 2018-2023 LinkedIn Corporation. All rights reserved.
+ * Copyright 2018-2024 LinkedIn Corporation. All rights reserved.
  * Licensed under the BSD-2 Clause license.
  * See LICENSE in the project root for license information.
  */
@@ -20,10 +20,11 @@
 
 
 /**
- * ConvertletTable for Hive Operators
+ * ConvertletTable for transformations only relevant to Coral's Intermediate Representation, not specific
+ * any SQL dialect. These transformations keep data parity between the SqlNode and RelNode layer, keeping the IR intact.
  * @see ReflectiveConvertletTable documentation for method naming and visibility rules
  */
-public class HiveConvertletTable extends ReflectiveConvertletTable {
+public class CoralConvertletTable extends ReflectiveConvertletTable {
 
   @SuppressWarnings("unused")
   public RexNode convertFunctionFieldReferenceOperator(SqlRexContext cx, FunctionFieldReferenceOperator op,
@@ -33,14 +34,15 @@ public RexNode convertFunctionFieldReferenceOperator(SqlRexContext cx, FunctionF
     return cx.getRexBuilder().makeFieldAccess(funcExpr, fieldName, false);
   }
 
+  /**
+   * Override {@link StandardConvertletTable#convertCast} to avoid cast optimizations that remove the cast.
+   */
   @SuppressWarnings("unused")
   public RexNode convertCast(SqlRexContext cx, SqlCastFunction cast, SqlCall call) {
     final SqlNode left = call.operand(0);
     RexNode leftRex = cx.convertExpression(left);
     SqlDataTypeSpec dataType = call.operand(1);
     RelDataType castType = dataType.deriveType(cx.getValidator(), true);
-    // can not call RexBuilder.makeCast() since that optimizes to remove the cast
-    // we don't want to remove the cast
     return cx.getRexBuilder().makeAbstractCast(castType, leftRex);
   }
 
diff --git a/coral-hive/src/main/java/com/linkedin/coral/hive/hive2rel/HiveToRelConverter.java b/coral-hive/src/main/java/com/linkedin/coral/hive/hive2rel/HiveToRelConverter.java
index 1b6b5b31d..f19b61800 100644
--- a/coral-hive/src/main/java/com/linkedin/coral/hive/hive2rel/HiveToRelConverter.java
+++ b/coral-hive/src/main/java/com/linkedin/coral/hive/hive2rel/HiveToRelConverter.java
@@ -70,7 +70,7 @@ public HiveFunctionResolver getFunctionResolver() {
 
   @Override
   protected SqlRexConvertletTable getConvertletTable() {
-    return new HiveConvertletTable();
+    return new CoralConvertletTable();
   }
 
   @Override
diff --git a/coral-trino/src/main/java/com/linkedin/coral/trino/trino2rel/TrinoToRelConverter.java b/coral-trino/src/main/java/com/linkedin/coral/trino/trino2rel/TrinoToRelConverter.java
index 2fc7ea6d6..25c2b6436 100644
--- a/coral-trino/src/main/java/com/linkedin/coral/trino/trino2rel/TrinoToRelConverter.java
+++ b/coral-trino/src/main/java/com/linkedin/coral/trino/trino2rel/TrinoToRelConverter.java
@@ -1,5 +1,5 @@
 /**
- * Copyright 2017-2023 LinkedIn Corporation. All rights reserved.
+ * Copyright 2017-2024 LinkedIn Corporation. All rights reserved.
  * Licensed under the BSD-2 Clause license.
  * See LICENSE in the project root for license information.
  */
@@ -24,8 +24,8 @@
 import com.linkedin.coral.common.HiveMetastoreClient;
 import com.linkedin.coral.common.HiveRelBuilder;
 import com.linkedin.coral.common.ToRelConverter;
+import com.linkedin.coral.hive.hive2rel.CoralConvertletTable;
 import com.linkedin.coral.hive.hive2rel.DaliOperatorTable;
-import com.linkedin.coral.hive.hive2rel.HiveConvertletTable;
 import com.linkedin.coral.hive.hive2rel.HiveSqlValidator;
 import com.linkedin.coral.hive.hive2rel.functions.HiveFunctionResolver;
 import com.linkedin.coral.hive.hive2rel.functions.StaticHiveFunctionRegistry;
@@ -63,7 +63,7 @@ public TrinoToRelConverter(Map<String, Map<String, List<String>>> localMetaStore
 
   @Override
   protected SqlRexConvertletTable getConvertletTable() {
-    return new HiveConvertletTable();
+    return new CoralConvertletTable();
   }
 
   @Override