Add map_string_as_varchar session property in ClickHouse

plugin/trino-clickhouse/src/main/java/io/trino/plugin/clickhouse/ClickHouseClient.java

@@ -69,6 +69,7 @@
 import static com.google.common.base.Preconditions.checkArgument;
 import static com.google.common.base.Strings.isNullOrEmpty;
 import static com.google.common.base.Verify.verify;
+import static io.trino.plugin.clickhouse.ClickHouseSessionProperties.isMapStringAsVarchar;
 import static io.trino.plugin.clickhouse.ClickHouseTableProperties.SAMPLE_BY_PROPERTY;
 import static io.trino.plugin.jdbc.DecimalConfig.DecimalMapping.ALLOW_OVERFLOW;
 import static io.trino.plugin.jdbc.DecimalSessionSessionProperties.getDecimalDefaultScale;
@@ -125,7 +126,6 @@ public class ClickHouseClient
 {
     static final int CLICKHOUSE_MAX_DECIMAL_PRECISION = 76;
 
-    private final boolean mapStringAsVarchar;
     private final AggregateFunctionRewriter<JdbcExpression> aggregateFunctionRewriter;
     private final Type uuidType;
 
@@ -134,13 +134,10 @@ public ClickHouseClient(
             BaseJdbcConfig config,
             ConnectionFactory connectionFactory,
             TypeManager typeManager,
-            ClickHouseConfig clickHouseConfig,
             IdentifierMapping identifierMapping)
     {
         super(config, "\"", connectionFactory, identifierMapping);
         this.uuidType = typeManager.getType(new TypeSignature(StandardTypes.UUID));
-        // TODO (https://github.com/trinodb/trino/issues/7102) define session property
-        this.mapStringAsVarchar = clickHouseConfig.isMapStringAsVarchar();
         JdbcTypeHandle bigintTypeHandle = new JdbcTypeHandle(Types.BIGINT, Optional.of("bigint"), Optional.empty(), Optional.empty(), Optional.empty(), Optional.empty());
         this.aggregateFunctionRewriter = new AggregateFunctionRewriter<>(
                 this::quoted,
@@ -384,7 +381,7 @@ public Optional<ColumnMapping> toColumnMapping(ConnectorSession session, Connect
 
             case "FixedString": // FixedString(n)
             case "String":
-                if (mapStringAsVarchar) {
+                if (isMapStringAsVarchar(session)) {
                     return Optional.of(ColumnMapping.sliceMapping(
                             createUnboundedVarcharType(),
                             varcharReadFunction(createUnboundedVarcharType()),

plugin/trino-clickhouse/src/main/java/io/trino/plugin/clickhouse/ClickHouseClientModule.java

@@ -28,6 +28,7 @@
 import io.trino.plugin.jdbc.credential.CredentialProvider;
 import ru.yandex.clickhouse.ClickHouseDriver;
 
+import static io.trino.plugin.jdbc.JdbcModule.bindSessionPropertiesProvider;
 import static io.trino.plugin.jdbc.JdbcModule.bindTablePropertiesProvider;
 
 public class ClickHouseClientModule
@@ -37,6 +38,7 @@ public class ClickHouseClientModule
     public void configure(Binder binder)
     {
         ConfigBinder.configBinder(binder).bindConfig(ClickHouseConfig.class);
+        bindSessionPropertiesProvider(binder, ClickHouseSessionProperties.class);
         binder.bind(JdbcClient.class).annotatedWith(ForBaseJdbc.class).to(ClickHouseClient.class).in(Scopes.SINGLETON);
         bindTablePropertiesProvider(binder, ClickHouseTableProperties.class);
         binder.install(new DecimalModule());

plugin/trino-clickhouse/src/main/java/io/trino/plugin/clickhouse/ClickHouseSessionProperties.java

@@ -0,0 +1,55 @@
+/*
+ * Licensed 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 io.trino.plugin.clickhouse;
+
+import com.google.common.collect.ImmutableList;
+import io.trino.plugin.base.session.SessionPropertiesProvider;
+import io.trino.spi.connector.ConnectorSession;
+import io.trino.spi.session.PropertyMetadata;
+
+import javax.inject.Inject;
+
+import java.util.List;
+
+import static io.trino.spi.session.PropertyMetadata.booleanProperty;
+
+public class ClickHouseSessionProperties
+        implements SessionPropertiesProvider
+{
+    public static final String MAP_STRING_AS_VARCHAR = "map_string_as_varchar";
+
+    private final List<PropertyMetadata<?>> sessionProperties;
+
+    @Inject
+    public ClickHouseSessionProperties(ClickHouseConfig clickHouseConfig)
+    {
+        sessionProperties = ImmutableList.of(
+                booleanProperty(
+                        MAP_STRING_AS_VARCHAR,
+                        "Map ClickHouse String and FixedString as varchar instead of varbinary",
+                        clickHouseConfig.isMapStringAsVarchar(),
+                        false));
+    }
+
+    @Override
+    public List<PropertyMetadata<?>> getSessionProperties()
+    {
+        return sessionProperties;
+    }
+
+    public static boolean isMapStringAsVarchar(ConnectorSession session)
+    {
+        return session.getProperty(MAP_STRING_AS_VARCHAR, Boolean.class);
+    }
+}

plugin/trino-clickhouse/src/test/java/io/trino/plugin/clickhouse/ClickHouseQueryRunner.java

@@ -33,7 +33,7 @@
 
 public final class ClickHouseQueryRunner
 {
-    private static final String TPCH_SCHEMA = "tpch";
+    public static final String TPCH_SCHEMA = "tpch";
 
     private ClickHouseQueryRunner() {}
 

plugin/trino-clickhouse/src/test/java/io/trino/plugin/clickhouse/TestClickHouseTypeMapping.java

@@ -37,6 +37,7 @@
 
 import static com.google.common.base.Preconditions.checkState;
 import static com.google.common.base.Verify.verify;
+import static io.trino.plugin.clickhouse.ClickHouseQueryRunner.TPCH_SCHEMA;
 import static io.trino.plugin.clickhouse.ClickHouseQueryRunner.createClickHouseQueryRunner;
 import static io.trino.spi.type.BigintType.BIGINT;
 import static io.trino.spi.type.DateType.DATE;
@@ -48,7 +49,9 @@
 import static io.trino.spi.type.TimestampType.createTimestampType;
 import static io.trino.spi.type.TinyintType.TINYINT;
 import static io.trino.spi.type.VarbinaryType.VARBINARY;
+import static io.trino.spi.type.VarcharType.VARCHAR;
 import static io.trino.spi.type.VarcharType.createUnboundedVarcharType;
+import static io.trino.testing.TestingSession.testSessionBuilder;
 import static java.lang.String.format;
 import static java.time.ZoneOffset.UTC;
 
@@ -238,6 +241,21 @@ public void testClickHouseChar()
                 .addRoundTrip("Nullable(char(10))", "'text_a'", VARBINARY, "to_utf8('text_a')")
                 .addRoundTrip("Nullable(char(1))", "'😂'", VARBINARY, "to_utf8('😂')")
                 .execute(getQueryRunner(), clickhouseCreateAndInsert("tpch.test_char"));
+
+        // Set map_string_as_varchar session property as true
+        SqlDataTypeTest.create()
+                // plain
+                .addRoundTrip("char(10)", "'text_a'", VARCHAR, "CAST('text_a' AS varchar)")
+                .addRoundTrip("char(255)", "'text_b'", VARCHAR, "CAST('text_b' AS varchar)")
+                .addRoundTrip("char(5)", "'攻殻機動隊'", VARCHAR, "CAST('攻殻機動隊' AS varchar)")
+                .addRoundTrip("char(32)", "'攻殻機動隊'", VARCHAR, "CAST('攻殻機動隊' AS varchar)")
+                .addRoundTrip("char(1)", "'😂'", VARCHAR, "CAST('😂' AS varchar)")
+                .addRoundTrip("char(77)", "'Ну, погоди!'", VARCHAR, "CAST('Ну, погоди!' AS varchar)")
+                // nullable
+                .addRoundTrip("Nullable(char(10))", "NULL", VARCHAR, "CAST(NULL AS varchar)")
+                .addRoundTrip("Nullable(char(10))", "'text_a'", VARCHAR, "CAST('text_a' AS varchar)")
+                .addRoundTrip("Nullable(char(1))", "'😂'", VARCHAR, "CAST('😂' AS varchar)")
+                .execute(getQueryRunner(), mapStringAsVarcharSession(), clickhouseCreateAndInsert("tpch.test_char"));
     }
 
     @Test
@@ -252,6 +270,17 @@ public void testClickHouseFixedString()
                 .addRoundTrip("Nullable(FixedString(10))", "'c12345678b'", VARBINARY, "to_utf8('c12345678b')")
                 .addRoundTrip("Nullable(FixedString(10))", "'c123'", VARBINARY, "to_utf8('c123\0\0\0\0\0\0')")
                 .execute(getQueryRunner(), clickhouseCreateAndInsert("tpch.test_fixed_string"));
+
+        // Set map_string_as_varchar session property as true
+        SqlDataTypeTest.create()
+                // plain
+                .addRoundTrip("FixedString(10)", "'c12345678b'", VARCHAR, "CAST('c12345678b' AS varchar)")
+                .addRoundTrip("FixedString(10)", "'c123'", VARCHAR, "CAST('c123\0\0\0\0\0\0' AS varchar)")
+                // nullable
+                .addRoundTrip("Nullable(FixedString(10))", "NULL", VARCHAR, "CAST(NULL AS varchar)")
+                .addRoundTrip("Nullable(FixedString(10))", "'c12345678b'", VARCHAR, "CAST('c12345678b' AS varchar)")
+                .addRoundTrip("Nullable(FixedString(10))", "'c123'", VARCHAR, "CAST('c123\0\0\0\0\0\0' AS varchar)")
+                .execute(getQueryRunner(), mapStringAsVarcharSession(), clickhouseCreateAndInsert("tpch.test_fixed_string"));
     }
 
     @Test
@@ -265,34 +294,65 @@ public void testTrinoChar()
                 .addRoundTrip("char(32)", "'攻殻機動隊'", VARBINARY, "to_utf8('攻殻機動隊')")
                 .addRoundTrip("char(1)", "'😂'", VARBINARY, "to_utf8('😂')")
                 .addRoundTrip("char(77)", "'Ну, погоди!'", VARBINARY, "to_utf8('Ну, погоди!')")
-                .execute(getQueryRunner(), trinoCreateAsSelect("test_char"));
+                .execute(getQueryRunner(), trinoCreateAsSelect("test_char"))
+                .execute(getQueryRunner(), trinoCreateAsSelect(mapStringAsVarcharSession(), "test_char"));
+
+        // Set map_string_as_varchar session property as true
+        SqlDataTypeTest.create()
+                .addRoundTrip("char(10)", "NULL", VARCHAR, "CAST(NULL AS varchar)")
+                .addRoundTrip("char(10)", "'text_a'", VARCHAR, "CAST('text_a' AS varchar)")
+                .addRoundTrip("char(255)", "'text_b'", VARCHAR, "CAST('text_b' AS varchar)")
+                .addRoundTrip("char(5)", "'攻殻機動隊'", VARCHAR, "CAST('攻殻機動隊' AS varchar)")
+                .addRoundTrip("char(32)", "'攻殻機動隊'", VARCHAR, "CAST('攻殻機動隊' AS varchar)")
+                .addRoundTrip("char(1)", "'😂'", VARCHAR, "CAST('😂' AS varchar)")
+                .addRoundTrip("char(77)", "'Ну, погоди!'", VARCHAR, "CAST('Ну, погоди!' AS varchar)")
+                .execute(getQueryRunner(), mapStringAsVarcharSession(), trinoCreateAsSelect("test_char"))
+                .execute(getQueryRunner(), mapStringAsVarcharSession(), trinoCreateAsSelect(mapStringAsVarcharSession(), "test_char"));
     }
 
     @Test
     public void testClickHouseVarchar()
     {
+        // TODO add more test cases
         // ClickHouse varchar is String, which is arbitrary bytes
         SqlDataTypeTest.create()
-                // TODO add more test cases
                 // plain
                 .addRoundTrip("varchar(30)", "'Piękna łąka w 東京都'", VARBINARY, "to_utf8('Piękna łąka w 東京都')")
                 // nullable
                 .addRoundTrip("Nullable(varchar(30))", "NULL", VARBINARY, "CAST(NULL AS varbinary)")
                 .addRoundTrip("Nullable(varchar(30))", "'Piękna łąka w 東京都'", VARBINARY, "to_utf8('Piękna łąka w 東京都')")
                 .execute(getQueryRunner(), clickhouseCreateAndInsert("tpch.test_varchar"));
+
+        // Set map_string_as_varchar session property as true
+        SqlDataTypeTest.create()
+                // plain
+                .addRoundTrip("varchar(30)", "'Piękna łąka w 東京都'", VARCHAR, "CAST('Piękna łąka w 東京都' AS varchar)")
+                // nullable
+                .addRoundTrip("Nullable(varchar(30))", "NULL", VARCHAR, "CAST(NULL AS varchar)")
+                .addRoundTrip("Nullable(varchar(30))", "'Piękna łąka w 東京都'", VARCHAR, "CAST('Piękna łąka w 東京都' AS varchar)")
+                .execute(getQueryRunner(), mapStringAsVarcharSession(), clickhouseCreateAndInsert("tpch.test_varchar"));
     }
 
     @Test
     public void testClickHouseString()
     {
+        // TODO add more test cases
         SqlDataTypeTest.create()
-                // TODO add more test cases
                 // plain
                 .addRoundTrip("String", "'Piękna łąka w 東京都'", VARBINARY, "to_utf8('Piękna łąka w 東京都')")
                 // nullable
                 .addRoundTrip("Nullable(String)", "NULL", VARBINARY, "CAST(NULL AS varbinary)")
                 .addRoundTrip("Nullable(String)", "'Piękna łąka w 東京都'", VARBINARY, "to_utf8('Piękna łąka w 東京都')")
                 .execute(getQueryRunner(), clickhouseCreateAndInsert("tpch.test_varchar"));
+
+        // Set map_string_as_varchar session property as true
+        SqlDataTypeTest.create()
+                // plain
+                .addRoundTrip("String", "'Piękna łąka w 東京都'", VARCHAR, "CAST('Piękna łąka w 東京都' AS varchar)")
+                // nullable
+                .addRoundTrip("Nullable(String)", "NULL", VARCHAR, "CAST(NULL AS varchar)")
+                .addRoundTrip("Nullable(String)", "'Piękna łąka w 東京都'", VARCHAR, "CAST('Piękna łąka w 東京都' AS varchar)")
+                .execute(getQueryRunner(), mapStringAsVarcharSession(), clickhouseCreateAndInsert("tpch.test_varchar"));
     }
 
     @Test
@@ -301,7 +361,15 @@ public void testTrinoVarchar()
         SqlDataTypeTest.create()
                 .addRoundTrip("varchar(30)", "NULL", VARBINARY, "CAST(NULL AS varbinary)")
                 .addRoundTrip("varchar(30)", "'Piękna łąka w 東京都'", VARBINARY, "to_utf8('Piękna łąka w 東京都')")
-                .execute(getQueryRunner(), trinoCreateAsSelect("test_varchar"));
+                .execute(getQueryRunner(), trinoCreateAsSelect("test_varchar"))
+                .execute(getQueryRunner(), trinoCreateAsSelect(mapStringAsVarcharSession(), "test_varchar"));
+
+        // Set map_string_as_varchar session property as true
+        SqlDataTypeTest.create()
+                .addRoundTrip("varchar(30)", "NULL", VARCHAR, "CAST(NULL AS varchar)")
+                .addRoundTrip("varchar(30)", "'Piękna łąka w 東京都'", VARCHAR, "CAST('Piękna łąka w 東京都' AS varchar)")
+                .execute(getQueryRunner(), mapStringAsVarcharSession(), trinoCreateAsSelect("test_varchar"))
+                .execute(getQueryRunner(), mapStringAsVarcharSession(), trinoCreateAsSelect(mapStringAsVarcharSession(), "test_varchar"));
     }
 
     @Test
@@ -425,6 +493,15 @@ public void testIp()
         // TODO add test with IPADDRESS written from Trino
     }
 
+    private static Session mapStringAsVarcharSession()
+    {
+        return testSessionBuilder()
+                .setCatalog("clickhouse")
+                .setSchema(TPCH_SCHEMA)
+                .setCatalogSessionProperty("clickhouse", "map_string_as_varchar", "true")
+                .build();
+    }
+
     private DataSetup trinoCreateAsSelect(String tableNamePrefix)
     {
         return trinoCreateAsSelect(getSession(), tableNamePrefix);