HHH-14456 Add DialectResolutionInfo#unwrap to be able to detect Cockroach in dialect resultion. Cleanup dialect resolution code.

hibernate-core/src/main/java/org/hibernate/boot/registry/selector/internal/DefaultDialectSelector.java

@@ -10,11 +10,17 @@ import java.util.Objects;
 
 import org.hibernate.dialect.CUBRIDDialect;
 import org.hibernate.dialect.Cache71Dialect;
+import org.hibernate.dialect.CacheDialect;
+import org.hibernate.dialect.CockroachDialect;
 import org.hibernate.dialect.DB2390Dialect;
 import org.hibernate.dialect.DB2390V8Dialect;
 import org.hibernate.dialect.DB2400Dialect;
 import org.hibernate.dialect.DB2400V7R3Dialect;
+import org.hibernate.dialect.DB297Dialect;
 import org.hibernate.dialect.DB2Dialect;
+import org.hibernate.dialect.DB2iDialect;
+import org.hibernate.dialect.DB2zDialect;
+import org.hibernate.dialect.DerbyDialect;
 import org.hibernate.dialect.DerbyTenFiveDialect;
 import org.hibernate.dialect.DerbyTenSevenDialect;
 import org.hibernate.dialect.DerbyTenSixDialect;
@@ -25,29 +31,52 @@ import org.hibernate.dialect.HANACloudColumnStoreDialect;
 import org.hibernate.dialect.HANAColumnStoreDialect;
 import org.hibernate.dialect.HANARowStoreDialect;
 import org.hibernate.dialect.HSQLDialect;
+import org.hibernate.dialect.Informix10Dialect;
 import org.hibernate.dialect.InformixDialect;
 import org.hibernate.dialect.Ingres10Dialect;
 import org.hibernate.dialect.Ingres9Dialect;
 import org.hibernate.dialect.IngresDialect;
+import org.hibernate.dialect.MariaDB102Dialect;
+import org.hibernate.dialect.MariaDB103Dialect;
+import org.hibernate.dialect.MariaDB10Dialect;
+import org.hibernate.dialect.MariaDB53Dialect;
+import org.hibernate.dialect.MariaDBDialect;
+import org.hibernate.dialect.MaxDBDialect;
 import org.hibernate.dialect.MimerSQLDialect;
+import org.hibernate.dialect.MySQL55Dialect;
 import org.hibernate.dialect.MySQL57Dialect;
 import org.hibernate.dialect.MySQL5Dialect;
 import org.hibernate.dialect.MySQL8Dialect;
+import org.hibernate.dialect.MySQLDialect;
 import org.hibernate.dialect.Oracle10gDialect;
+import org.hibernate.dialect.Oracle12cDialect;
 import org.hibernate.dialect.Oracle8iDialect;
 import org.hibernate.dialect.Oracle9iDialect;
+import org.hibernate.dialect.OracleDialect;
 import org.hibernate.dialect.PostgreSQL81Dialect;
 import org.hibernate.dialect.PostgreSQL82Dialect;
+import org.hibernate.dialect.PostgreSQL91Dialect;
+import org.hibernate.dialect.PostgreSQL92Dialect;
+import org.hibernate.dialect.PostgreSQL93Dialect;
+import org.hibernate.dialect.PostgreSQL94Dialect;
+import org.hibernate.dialect.PostgreSQL95Dialect;
 import org.hibernate.dialect.PostgreSQL9Dialect;
+import org.hibernate.dialect.PostgreSQLDialect;
 import org.hibernate.dialect.PostgresPlusDialect;
+import org.hibernate.dialect.RDMSOS2200Dialect;
 import org.hibernate.dialect.SAPDBDialect;
 import org.hibernate.dialect.SQLServer2005Dialect;
 import org.hibernate.dialect.SQLServer2008Dialect;
+import org.hibernate.dialect.SQLServer2012Dialect;
 import org.hibernate.dialect.SQLServerDialect;
+import org.hibernate.dialect.SpannerDialect;
 import org.hibernate.dialect.Sybase11Dialect;
 import org.hibernate.dialect.SybaseASE157Dialect;
 import org.hibernate.dialect.SybaseASE15Dialect;
+import org.hibernate.dialect.SybaseASEDialect;
 import org.hibernate.dialect.SybaseAnywhereDialect;
+import org.hibernate.dialect.SybaseDialect;
+import org.hibernate.dialect.Teradata14Dialect;
 import org.hibernate.dialect.TeradataDialect;
 import org.hibernate.dialect.TimesTenDialect;
 
@@ -59,195 +88,147 @@ public class DefaultDialectSelector implements LazyServiceResolver<Dialect> {
 		if ( name.isEmpty() ) {
 			return null;
 		}
-		//Let's organize all string matches in groups by first letter:
+		switch ( name ) {
-		final char n = name.charAt( 0 );
+			case "Cache":
-		switch ( n ) {
+				return CacheDialect.class;
-			case 'C': return caseC( name );
+			case "Cache71":
-			case 'D': return caseD( name );
+				return Cache71Dialect.class;
-			case 'F': return caseF( name );
+			case "Cockroach":
-			case 'H': return caseH( name );
+				return CockroachDialect.class;
-			case 'I': return caseI( name );
+			case "CUBRID":
-			case 'M': return caseM( name );
+				return CUBRIDDialect.class;
-			case 'O': return caseO( name );
+			case "DB2":
-			case 'P': return caseP( name );
+				return DB2Dialect.class;
-			case 'S': return caseS( name );
+			case "DB2i":
-			case 'T': return caseT( name );
+				return DB2iDialect.class;
-		}
+			case "DB2z":
-		return null;
+				return DB2zDialect.class;
-	}
+			case "DB297":
-
+				return DB297Dialect.class;
-	private static Class<? extends Dialect> caseC(final String name) {
+			case "DB2390":
-		if ( name.equals( "Cache71" ) ) {
+				return DB2390Dialect.class;
-			return Cache71Dialect.class;
+			case "DB2390V8":
-		}
+				return DB2390V8Dialect.class;
-		// todo (6.0): add CockroachDB
+			case "DB2400":
-//		if ( name.equals( "CockroachDB192" ) ) {
+				return DB2400Dialect.class;
-//			return CockroachDB192Dialect.class;
+			case "DB2400V7R3":
-//		}
+				return DB2400V7R3Dialect.class;
-//		if ( name.equals( "CockroachDB201" ) ) {
+			case "Derby":
-//			return CockroachDB201Dialect.class;
+				return DerbyDialect.class;
-//		}
+			case "DerbyTenFive":
-		if ( name.equals( "CUBRID" ) ) {
+				return DerbyTenFiveDialect.class;
-			return CUBRIDDialect.class;
+			case "DerbyTenSix":
-		}
+				return DerbyTenSixDialect.class;
-		return null;
+			case "DerbyTenSeven":
-	}
+				return DerbyTenSevenDialect.class;
-
+			case "Firebird":
-	private static Class<? extends Dialect> caseD(final String name) {
+				return FirebirdDialect.class;
-		if ( name.equals( "DB2" ) ) {
+			case "H2":
-			return DB2Dialect.class;
+				return H2Dialect.class;
-		}
+			case "HANACloudColumnStore":
-		if ( name.equals( "DB2390" ) ) {
+				return HANACloudColumnStoreDialect.class;
-			return DB2390Dialect.class;
+			case "HANAColumnStore":
-		}
+				return HANAColumnStoreDialect.class;
-		if ( name.equals( "DB2390V8" ) ) {
+			case "HANARowStore":
-			return DB2390V8Dialect.class;
+				return HANARowStoreDialect.class;
-		}
+			case "HSQL":
-		if ( name.equals( "DB2400" ) ) {
+				return HSQLDialect.class;
-			return DB2400Dialect.class;
+			case "Informix":
-		}
+				return InformixDialect.class;
-		if ( name.equals( "DB2400V7R3" ) ) {
+			case "Informix10":
-			return DB2400V7R3Dialect.class;
+				return Informix10Dialect.class;
-		}
+			case "Ingres":
-		if ( name.equals( "DerbyTenFive" ) ) {
+				return IngresDialect.class;
-			return DerbyTenFiveDialect.class;
+			case "Ingres9":
-		}
+				return Ingres9Dialect.class;
-		if ( name.equals( "DerbyTenSix" ) ) {
+			case "Ingres10":
-			return DerbyTenSixDialect.class;
+				return Ingres10Dialect.class;
-		}
+			case "MariaDB":
-		if ( name.equals( "DerbyTenSeven" ) ) {
+				return MariaDBDialect.class;
-			return DerbyTenSevenDialect.class;
+			case "MariaDB53":
-		}
+				return MariaDB53Dialect.class;
-		return null;
+			case "MariaDB10":
-	}
+				return MariaDB10Dialect.class;
-
+			case "MariaDB102":
-	private static Class<? extends Dialect> caseF(final String name) {
+				return MariaDB102Dialect.class;
-		if ( name.equals( "Firebird" ) ) {
+			case "MariaDB103":
-			return FirebirdDialect.class;
+				return MariaDB103Dialect.class;
-		}
+			case "MaxDB":
-		return null;
+				return MaxDBDialect.class;
-	}
+			case "MimerSQL":
-
+				return MimerSQLDialect.class;
-	private static Class<? extends Dialect> caseH(final String name) {
+			case "MySQL":
-		if ( name.equals( "H2" ) ) {
+				return MySQLDialect.class;
-			return H2Dialect.class;
+			case "MySQL5":
-		}
+				return MySQL5Dialect.class;
-		if ( name.equals( "HANACloudColumnStore" ) ) {
+			case "MySQL55":
-			return HANACloudColumnStoreDialect.class;
+				return MySQL55Dialect.class;
-		}
+			case "MySQL57":
-		if ( name.equals( "HANAColumnStore" ) ) {
+				return MySQL57Dialect.class;
-			return HANAColumnStoreDialect.class;
+			case "MySQL8":
-		}
+				return MySQL8Dialect.class;
-		if ( name.equals( "HANARowStore" ) ) {
+			case "Oracle":
-			return HANARowStoreDialect.class;
+				return OracleDialect.class;
-		}
+			case "Oracle8i":
-		if ( name.equals( "HSQL" ) ) {
+				return Oracle8iDialect.class;
-			return HSQLDialect.class;
+			case "Oracle9i":
-		}
+				return Oracle9iDialect.class;
-		return null;
+			case "Oracle10g":
-	}
+				return Oracle10gDialect.class;
-
+			case "Oracle12c":
-	private static Class<? extends Dialect> caseI(final String name) {
+				return Oracle12cDialect.class;
-		if ( name.equals( "Informix" ) ) {
+			case "PostgresPlus":
-			return InformixDialect.class;
+				return PostgresPlusDialect.class;
-		}
+			case "PostgreSQL":
-		if ( name.equals( "Ingres" ) ) {
+				return PostgreSQLDialect.class;
-			return IngresDialect.class;
+			case "PostgreSQL81":
-		}
+				return PostgreSQL81Dialect.class;
-		if ( name.equals( "Ingres9" ) ) {
+			case "PostgreSQL82":
-			return Ingres9Dialect.class;
+				return PostgreSQL82Dialect.class;
-		}
+			case "PostgreSQL9":
-		if ( name.equals( "Ingres10" ) ) {
+				return PostgreSQL9Dialect.class;
-			return Ingres10Dialect.class;
+			case "PostgreSQL91":
-		}
+				return PostgreSQL91Dialect.class;
-		return null;
+			case "PostgreSQL92":
-	}
+				return PostgreSQL92Dialect.class;
-
+			case "PostgreSQL93":
-	private static Class<? extends Dialect> caseM(final String name) {
+				return PostgreSQL93Dialect.class;
-		if ( name.equals( "MimerSQL" ) ) {
+			case "PostgreSQL94":
-			return MimerSQLDialect.class;
+				return PostgreSQL94Dialect.class;
-		}
+			case "PostgreSQL95":
-		if ( name.equals( "MySQL5" ) ) {
+				return PostgreSQL95Dialect.class;
-			return MySQL5Dialect.class;
+			case "RDMSOS2200":
-		}
+				return RDMSOS2200Dialect.class;
-		if ( name.equals( "MySQL57" ) ) {
+			case "SAPDB":
-			return MySQL57Dialect.class;
+				return SAPDBDialect.class;
-		}
+			case "Spanner":
-		if ( name.equals( "MySQL8" ) ) {
+				return SpannerDialect.class;
-			return MySQL8Dialect.class;
+			case "SQLServer":
-		}
+				return SQLServerDialect.class;
-		return null;
+			case "SQLServer2005":
-	}
+				return SQLServer2005Dialect.class;
-
+			case "SQLServer2008":
-	private static Class<? extends Dialect> caseO(final String name) {
+				return SQLServer2008Dialect.class;
-		if ( name.equals( "Oracle8i" ) ) {
+			case "SQLServer2012":
-			return Oracle8iDialect.class;
+				return SQLServer2012Dialect.class;
-		}
+			case "Sybase":
-		if ( name.equals( "Oracle9i" ) ) {
+				return SybaseDialect.class;
-			return Oracle9iDialect.class;
+			case "Sybase11":
-		}
+				return Sybase11Dialect.class;
-		if ( name.equals( "Oracle10g" ) ) {
+			case "SybaseAnywhere":
-			return Oracle10gDialect.class;
+				return SybaseAnywhereDialect.class;
-		}
+			case "SybaseASE":
-		return null;
+				return SybaseASEDialect.class;
-	}
+			case "SybaseASE15":
-
+				return SybaseASE15Dialect.class;
-	private static Class<? extends Dialect> caseP(final String name) {
+			case "SybaseASE157":
-		if ( name.equals( "PostgresPlus" ) ) {
+				return SybaseASE157Dialect.class;
-			return PostgresPlusDialect.class;
+			case "Teradata":
-		}
+				return TeradataDialect.class;
-		if ( name.equals( "PostgreSQL81" ) ) {
+			case "Teradata14":
-			return PostgreSQL81Dialect.class;
+				return Teradata14Dialect.class;
-		}
+			case "TimesTen":
-		if ( name.equals( "PostgreSQL82" ) ) {
+				return TimesTenDialect.class;
-			return PostgreSQL82Dialect.class;
-		}
-		if ( name.equals( "PostgreSQL9" ) ) {
-			return PostgreSQL9Dialect.class;
-		}
-		return null;
-	}
-
-	private static Class<? extends Dialect> caseS(final String name) {
-		if ( name.equals( "SAPDB" ) ) {
-			return SAPDBDialect.class;
-		}
-		if ( name.equals( "SQLServer" ) ) {
-			return SQLServerDialect.class;
-		}
-		if ( name.equals( "SQLServer2005" ) ) {
-			return SQLServer2005Dialect.class;
-		}
-		if ( name.equals( "SQLServer2008" ) ) {
-			return SQLServer2008Dialect.class;
-		}
-		if ( name.equals( "Sybase11" ) ) {
-			return Sybase11Dialect.class;
-		}
-		if ( name.equals( "SybaseAnywhere" ) ) {
-			return SybaseAnywhereDialect.class;
-		}
-		if ( name.equals( "Sybase11" ) ) {
-			return Sybase11Dialect.class;
-		}
-		if ( name.equals( "SybaseAnywhere" ) ) {
-			return SybaseAnywhereDialect.class;
-		}
-		if ( name.equals( "SybaseASE15" ) ) {
-			return SybaseASE15Dialect.class;
-		}
-		if ( name.equals( "SybaseASE157" ) ) {
-			return SybaseASE157Dialect.class;
-		}
-		return null;
-	}
-
-	private static Class<? extends Dialect> caseT(final String name) {
-		if ( name.equals( "Teradata" ) ) {
-			return TeradataDialect.class;
-		}
-		if ( name.equals( "TimesTen" ) ) {
-			return TimesTenDialect.class;
 		}
 		return null;
 	}

hibernate-core/src/main/java/org/hibernate/dialect/Database.java

@@ -6,6 +6,12 @@
  */
 package org.hibernate.dialect;
 
+import java.sql.DatabaseMetaData;
+import java.sql.ResultSet;
+import java.sql.SQLException;
+import java.sql.Statement;
+
+import org.hibernate.engine.jdbc.dialect.spi.BasicSQLExceptionConverter;
 import org.hibernate.engine.jdbc.dialect.spi.DialectResolutionInfo;
 
 /**
@@ -77,7 +83,7 @@ public enum Database {
 	DERBY {
 		@Override
 		public Dialect createDialect(DialectResolutionInfo info) {
-			return new DerbyDialect(info);
+			return new DerbyDialect( info );
 		}
 		@Override
 		public boolean productNameMatches(String databaseName) {
@@ -85,7 +91,7 @@ public enum Database {
 		}
 		@Override
 		public String getDriverClassName(String jdbcUrl) {
-			return jdbcUrl.startsWith("jdbc:derby://")
+			return jdbcUrl.startsWith( "jdbc:derby://" )
 					? "org.apache.derby.jdbc.ClientDriver"
 					: "org.apache.derby.jdbc.EmbeddedDriver";
 		}
@@ -94,7 +100,7 @@ public enum Database {
 	ENTERPRISEDB {
 		@Override
 		public Dialect createDialect(DialectResolutionInfo info) {
-			return new PostgresPlusDialect();
+			return new PostgresPlusDialect( info );
 		}
 		@Override
 		public boolean productNameMatches(String databaseName) {
@@ -113,7 +119,7 @@ public enum Database {
 	FIREBIRD {
 		@Override
 		public Dialect createDialect(DialectResolutionInfo info) {
-			return new FirebirdDialect(info);
+			return new FirebirdDialect( info );
 		}
 		@Override
 		public boolean productNameMatches(String databaseName) {
@@ -132,7 +138,7 @@ public enum Database {
 	H2 {
 		@Override
 		public Dialect createDialect(DialectResolutionInfo info) {
-			return new H2Dialect(info);
+			return new H2Dialect( info );
 		}
 		@Override
 		public boolean productNameMatches(String databaseName) {
@@ -147,7 +153,7 @@ public enum Database {
 	HANA {
 		@Override
 		public Dialect createDialect(DialectResolutionInfo info) {
-			return new HANAColumnStoreDialect(info);
+			return new HANAColumnStoreDialect( info );
 		}
 		@Override
 		public boolean productNameMatches(String databaseName) {
@@ -166,7 +172,7 @@ public enum Database {
 	HSQL {
 		@Override
 		public Dialect createDialect(DialectResolutionInfo info) {
-			return new HSQLDialect(info);
+			return new HSQLDialect( info );
 		}
 		@Override
 		public boolean productNameMatches(String databaseName) {
@@ -185,12 +191,12 @@ public enum Database {
 	INFORMIX {
 		@Override
 		public Dialect createDialect(DialectResolutionInfo info) {
-			return new InformixDialect(info);
+			return new InformixDialect( info );
 		}
 		@Override
 		public boolean productNameMatches(String databaseName) {
 			//usually "Informix Dynamic Server"
-			return databaseName.toLowerCase().startsWith("informix");
+			return databaseName.toLowerCase().startsWith( "informix" );
 		}
 		@Override
 		public String getDriverClassName(String jdbcUrl) {
@@ -205,11 +211,11 @@ public enum Database {
 	INGRES {
 		@Override
 		public Dialect createDialect(DialectResolutionInfo info) {
-			return new IngresDialect(info);
+			return new IngresDialect( info );
 		}
 		@Override
 		public boolean productNameMatches(String databaseName) {
-			return databaseName.toLowerCase().startsWith("ingres");
+			return databaseName.toLowerCase().startsWith( "ingres" );
 		}
 		@Override
 		public String getDriverClassName(String jdbcUrl) {
@@ -226,12 +232,12 @@ public enum Database {
 			else {
 				//in case the product name has been set to MySQL
 				String driverName = info.getDriverName();
-				return driverName != null && driverName.startsWith("MariaDB");
+				return driverName != null && driverName.startsWith( "MariaDB" );
 			}
 		}
 		@Override
 		public Dialect createDialect(DialectResolutionInfo info) {
-			return new MariaDBDialect(info);
+			return new MariaDBDialect( info );
 		}
 		@Override
 		public boolean productNameMatches(String productName) {
@@ -250,8 +256,8 @@ public enum Database {
 		}
 		@Override
 		public boolean productNameMatches(String databaseName) {
-			return databaseName.toLowerCase().startsWith("sap db")
+			return databaseName.toLowerCase().startsWith( "sap db" )
-				|| databaseName.toLowerCase().startsWith("maxdb");
+					|| databaseName.toLowerCase().startsWith( "maxdb" );
 		}
 		@Override
 		public String getDriverClassName(String jdbcUrl) {
@@ -270,7 +276,7 @@ public enum Database {
 		}
 		@Override
 		public boolean productNameMatches(String databaseName) {
-			return databaseName.startsWith("Mimer SQL");
+			return databaseName.startsWith( "Mimer SQL" );
 		}
 		@Override
 		public String getDriverClassName(String jdbcUrl) {
@@ -281,7 +287,7 @@ public enum Database {
 	MYSQL {
 		@Override
 		public Dialect createDialect(DialectResolutionInfo info) {
-			return new MySQLDialect(info);
+			return new MySQLDialect( info );
 		}
 		@Override
 		public boolean productNameMatches(String databaseName) {
@@ -296,7 +302,7 @@ public enum Database {
 	ORACLE {
 		@Override
 		public Dialect createDialect(DialectResolutionInfo info) {
-			return new OracleDialect(info);
+			return new OracleDialect( info );
 		}
 		@Override
 		public boolean productNameMatches(String databaseName) {
@@ -311,7 +317,11 @@ public enum Database {
 	POSTGRESQL {
 		@Override
 		public Dialect createDialect(DialectResolutionInfo info) {
-			return new PostgreSQLDialect(info);
+			final String version = getVersion( info.unwrap( DatabaseMetaData.class ) );
+			if ( version.startsWith( "Cockroach" ) ) {
+				return new CockroachDialect( info );
+			}
+			return new PostgreSQLDialect( info );
 		}
 		@Override
 		public boolean productNameMatches(String databaseName) {
@@ -321,12 +331,39 @@ public enum Database {
 		public String getDriverClassName(String jdbcUrl) {
 			return "org.postgresql.Driver";
 		}
+		private String getVersion(DatabaseMetaData databaseMetaData) {
+			try (Statement statement = databaseMetaData.getConnection().createStatement() ) {
+				final ResultSet rs = statement.executeQuery( "select version()" );
+				if ( rs.next() ) {
+					return rs.getString( 1 );
+				}
+			}
+			catch (SQLException e) {
+				throw BasicSQLExceptionConverter.INSTANCE.convert( e );
+			}
+			return "";
+		}
+	},
+
+	SPANNER {
+		@Override
+		public Dialect createDialect(DialectResolutionInfo info) {
+			return new SpannerDialect();
+		}
+		@Override
+		public boolean productNameMatches(String databaseName) {
+			return databaseName.startsWith( "Google Cloud Spanner" );
+		}
+		@Override
+		public String getDriverClassName(String jdbcUrl) {
+			return "com.google.cloud.spanner.jdbc.JdbcDriver";
+		}
 	},
 
 	SQLSERVER {
 		@Override
 		public Dialect createDialect(DialectResolutionInfo info) {
-			return new SQLServerDialect(info);
+			return new SQLServerDialect( info );
 		}
 		@Override
 		public boolean productNameMatches(String databaseName) {
@@ -343,7 +380,7 @@ public enum Database {
 		public Dialect createDialect(DialectResolutionInfo info) {
 			final String databaseName = info.getDatabaseName();
 			if ( isASE( databaseName ) ) {
-				return new SybaseASEDialect(info);
+				return new SybaseASEDialect( info );
 			}
 			if ( isASA( databaseName ) ) {
 				return new SybaseAnywhereDialect();
@@ -364,15 +401,15 @@ public enum Database {
 		}
 		@Override
 		public boolean matchesUrl(String jdbcUrl) {
-			return jdbcUrl.startsWith("jdbc:sybase:")
+			return jdbcUrl.startsWith( "jdbc:sybase:" )
-				|| jdbcUrl.startsWith("jdbc:sqlanywhere:");
+					|| jdbcUrl.startsWith( "jdbc:sqlanywhere:" );
 		}
 	},
 
 	TERADATA {
 		@Override
 		public Dialect createDialect(DialectResolutionInfo info) {
-			return new TeradataDialect(info);
+			return new TeradataDialect( info );
 		}
 		@Override
 		public boolean productNameMatches(String databaseName) {
@@ -391,7 +428,7 @@ public enum Database {
 		}
 		@Override
 		public boolean productNameMatches(String databaseName) {
-			return databaseName.toLowerCase().startsWith("timesten");
+			return databaseName.toLowerCase().startsWith( "timesten" );
 		}
 	};
 

hibernate-core/src/main/java/org/hibernate/dialect/PostgreSQLDialect.java

@@ -82,7 +82,7 @@ public class PostgreSQLDialect extends Dialect {
 	}
 
 	public PostgreSQLDialect() {
-		this(800);
+		this( 800 );
 	}
 
 	public PostgreSQLDialect(int version) {

hibernate-core/src/main/java/org/hibernate/dialect/PostgresPlusDialect.java

@@ -11,6 +11,7 @@ import java.sql.SQLException;
 import java.sql.Types;
 
 import org.hibernate.dialect.function.CommonFunctionFactory;
+import org.hibernate.engine.jdbc.dialect.spi.DialectResolutionInfo;
 import org.hibernate.query.spi.QueryEngine;
 
 /**
@@ -19,6 +20,7 @@ import org.hibernate.query.spi.QueryEngine;
  * @author Jim Mlodgenski
  */
 public class PostgresPlusDialect extends PostgreSQLDialect {
+
 	/**
 	 * Constructs a PostgresPlusDialect
 	 */
@@ -26,6 +28,14 @@ public class PostgresPlusDialect extends PostgreSQLDialect {
 		super();
 	}
 
+	public PostgresPlusDialect(DialectResolutionInfo info) {
+		super( info );
+	}
+
+	public PostgresPlusDialect(int version) {
+		super( version );
+	}
+
 	@Override
 	public void initializeFunctionRegistry(QueryEngine queryEngine) {
 		super.initializeFunctionRegistry( queryEngine );

hibernate-core/src/main/java/org/hibernate/engine/jdbc/dialect/internal/DialectFactoryImpl.java

@@ -55,9 +55,9 @@ public class DialectFactoryImpl implements DialectFactory, ServiceRegistryAwareS
 	@Override
 	public Dialect buildDialect(Map configValues, DialectResolutionInfoSource resolutionInfoSource) throws HibernateException {
 		final Object dialectReference = configValues.get( AvailableSettings.DIALECT );
-		Dialect dialect = !isEmpty(dialectReference) ?
+		Dialect dialect = !isEmpty( dialectReference ) ?
-				constructDialect(dialectReference, resolutionInfoSource) :
+				constructDialect( dialectReference, resolutionInfoSource ) :
-				determineDialect(resolutionInfoSource);
+				determineDialect( resolutionInfoSource );
 		logSelectedDialect( dialect );
 		return dialect;
 	}
@@ -66,10 +66,10 @@ public class DialectFactoryImpl implements DialectFactory, ServiceRegistryAwareS
 		LOG.usingDialect( dialect );
 
 		Class<? extends Dialect> dialectClass = dialect.getClass();
-		if ( dialectClass.isAnnotationPresent(Deprecated.class) ) {
+		if ( dialectClass.isAnnotationPresent( Deprecated.class ) ) {
 			Class<?> superDialectClass = dialectClass.getSuperclass();
-			if ( !superDialectClass.isAnnotationPresent(Deprecated.class)
+			if ( !superDialectClass.isAnnotationPresent( Deprecated.class )
-					&& !superDialectClass.equals(Dialect.class) ) {
+					&& !superDialectClass.equals( Dialect.class ) ) {
 				DEPRECATION_LOGGER.deprecatedDialect( dialectClass.getSimpleName(), superDialectClass.getName() );
 			}
 			else {
@@ -101,7 +101,7 @@ public class DialectFactoryImpl implements DialectFactory, ServiceRegistryAwareS
 						try {
 							try {
 								if (resolutionInfoSource != null) {
-									return dialectClass.getConstructor(DialectResolutionInfo.class).newInstance(
+									return dialectClass.getConstructor( DialectResolutionInfo.class ).newInstance(
 											resolutionInfoSource.getDialectResolutionInfo()
 									);
 								}

hibernate-core/src/main/java/org/hibernate/engine/jdbc/dialect/spi/DatabaseMetaDataDialectResolutionInfoAdapter.java

@@ -87,4 +87,12 @@ public class DatabaseMetaDataDialectResolutionInfoAdapter implements DialectReso
 	public int getDriverMinorVersion() {
 		return interpretVersion( databaseMetaData.getDriverMinorVersion() );
 	}
+
+	@Override
+	public <T> T unwrap(Class<T> clazz) {
+		if ( clazz.isInstance( databaseMetaData ) ) {
+			return clazz.cast( databaseMetaData );
+		}
+		return null;
+	}
 }

hibernate-core/src/main/java/org/hibernate/engine/jdbc/dialect/spi/DialectResolutionInfo.java

@@ -91,5 +91,15 @@ public interface DialectResolutionInfo {
 	 */
 	public int getDriverMinorVersion();
 
+	/**
+	 * Obtain access to the underlying object of the given type.
+	 *
+	 * Return <code>null</code> if the underlying object is not of the given type.
+	 *
+	 * @return The unwrapped object or <code>null</code>
+	 */
+	default <T> T unwrap(Class<T> clazz) {
+		return null;
+	}
 
 }