From 62c0277738bce804be84e950faf03488701d35c7 Mon Sep 17 00:00:00 2001
From: Kevin Ge <kge@linkedin.com>
Date: Thu, 5 Oct 2023 13:51:49 -0400
Subject: [PATCH] remove char sets from TrinoSqlDialect

---
 .../coral/trino/rel2trino/TrinoSqlDialect.java      |  5 -----
 .../coral/trino/rel2trino/TrinoSqlRewriter.java     |  8 ++++++++
 .../trino/rel2trino/HiveToTrinoConverterTest.java   | 13 +++++++++++++
 3 files changed, 21 insertions(+), 5 deletions(-)

diff --git a/coral-trino/src/main/java/com/linkedin/coral/trino/rel2trino/TrinoSqlDialect.java b/coral-trino/src/main/java/com/linkedin/coral/trino/rel2trino/TrinoSqlDialect.java
index fa0f54739..460575d42 100644
--- a/coral-trino/src/main/java/com/linkedin/coral/trino/rel2trino/TrinoSqlDialect.java
+++ b/coral-trino/src/main/java/com/linkedin/coral/trino/rel2trino/TrinoSqlDialect.java
@@ -25,11 +25,6 @@ private TrinoSqlDialect(Context context) {
     super(context);
   }
 
-  @Override
-  public boolean supportsCharSet() {
-    return false;
-  }
-
   /**
    * Override this method so that so that table alias is prepended to all field references (e.g., "table.column"
    * or "table.struct.filed" instead of "column" or "struct.field"), which is necessary for
diff --git a/coral-trino/src/main/java/com/linkedin/coral/trino/rel2trino/TrinoSqlRewriter.java b/coral-trino/src/main/java/com/linkedin/coral/trino/rel2trino/TrinoSqlRewriter.java
index 823b89b7c..20207e7fe 100644
--- a/coral-trino/src/main/java/com/linkedin/coral/trino/rel2trino/TrinoSqlRewriter.java
+++ b/coral-trino/src/main/java/com/linkedin/coral/trino/rel2trino/TrinoSqlRewriter.java
@@ -60,6 +60,14 @@ private static SqlDataTypeSpec convertTypeSpec(SqlDataTypeSpec type) {
           final SqlBasicTypeNameSpec realTypeName =
               new SqlBasicTypeNameSpec(SqlTypeName.REAL, precision, scale, charSetName, parserPos);
           return new SqlDataTypeSpec(realTypeName, timeZone, parserPos);
+        case "VARCHAR":
+          final SqlBasicTypeNameSpec varcharTypeName =
+              new SqlBasicTypeNameSpec(SqlTypeName.VARCHAR, precision, scale, null, parserPos); // remove CHARACTER SET
+          return new SqlDataTypeSpec(varcharTypeName, timeZone, parserPos);
+        case "CHAR":
+          final SqlBasicTypeNameSpec charTypeName =
+              new SqlBasicTypeNameSpec(SqlTypeName.CHAR, precision, scale, null, parserPos); // remove CHARACTER SET
+          return new SqlDataTypeSpec(charTypeName, timeZone, parserPos);
         default:
           return type;
       }
diff --git a/coral-trino/src/test/java/com/linkedin/coral/trino/rel2trino/HiveToTrinoConverterTest.java b/coral-trino/src/test/java/com/linkedin/coral/trino/rel2trino/HiveToTrinoConverterTest.java
index 816df7bc0..0c5f8c91b 100644
--- a/coral-trino/src/test/java/com/linkedin/coral/trino/rel2trino/HiveToTrinoConverterTest.java
+++ b/coral-trino/src/test/java/com/linkedin/coral/trino/rel2trino/HiveToTrinoConverterTest.java
@@ -380,6 +380,19 @@ public void testNamedStructWithArrayWithoutType() {
     assertEquals(expandedSql, targetSql);
   }
 
+  @Test
+  public void testNestedNamedStructWithArrayWithoutType() {
+    RelNode relNode =
+        TestUtils.getHiveToRelConverter().convertSql("SELECT NAMED_STRUCT('value', NAMED_STRUCT('value2', ARRAY()))");
+    String targetSql =
+        "SELECT CAST(ROW(CAST(ROW(ARRAY[]) AS ROW(\"value2\" ARRAY<VARCHAR(65535)>))) AS ROW(\"value\" ROW(\"value2\" ARRAY<VARCHAR(65535)>)))\n"
+            + "FROM (VALUES  (0)) AS \"t\" (\"ZERO\")";
+
+    RelToTrinoConverter relToTrinoConverter = TestUtils.getRelToTrinoConverter();
+    String expandedSql = relToTrinoConverter.convert(relNode);
+    assertEquals(expandedSql, targetSql);
+  }
+
   @Test
   public void testNamedStructWithStringTypeArray() {
     RelNode relNode =