Polishing.

Push JDBC-specific simple types into JdbcPostgresDialect instead of having these in the top-level dialect that shouldn't be tied to any driver technology.

Introduce profile to run Postgres tests only.

spring-data-jdbc/pom.xml

@@ -237,6 +237,37 @@
 
 
 	<profiles>
+		<profile>
+			<id>postgres</id>
+			<build>
+				<plugins>
+					<plugin>
+						<groupId>org.apache.maven.plugins</groupId>
+						<artifactId>maven-surefire-plugin</artifactId>
+						<executions>
+							<execution>
+								<id>postgres-test</id>
+								<phase>test</phase>
+								<goals>
+									<goal>test</goal>
+								</goals>
+								<configuration>
+									<includes>
+										<include>**/*IntegrationTests.java</include>
+									</includes>
+									<excludes>
+										<exclude>**/*HsqlIntegrationTests.java</exclude>
+									</excludes>
+									<systemPropertyVariables>
+										<spring.profiles.active>postgres</spring.profiles.active>
+									</systemPropertyVariables>
+								</configuration>
+							</execution>
+						</executions>
+					</plugin>
+				</plugins>
+			</build>
+		</profile>
 		<profile>
 			<id>all-dbs</id>
 			<build>

spring-data-jdbc/src/main/java/org/springframework/data/jdbc/aot/JdbcRuntimeHints.java

@@ -16,7 +16,6 @@
 package org.springframework.data.jdbc.aot;
 
 import java.util.Arrays;
-import java.util.UUID;
 
 import org.springframework.aot.hint.MemberCategory;
 import org.springframework.aot.hint.RuntimeHints;
@@ -63,7 +62,5 @@ class JdbcRuntimeHints implements RuntimeHintsRegistrar {
 		for (Class<?> simpleType : JdbcPostgresDialect.INSTANCE.simpleTypes()) {
 			hints.reflection().registerType(TypeReference.of(simpleType), MemberCategory.PUBLIC_CLASSES);
 		}
-
-		hints.reflection().registerType(TypeReference.of(UUID.class.getName()), MemberCategory.PUBLIC_CLASSES);
 	}
 }

spring-data-jdbc/src/main/java/org/springframework/data/jdbc/core/dialect/JdbcPostgresDialect.java

@@ -23,9 +23,13 @@ import java.sql.Types;
 import java.util.Arrays;
 import java.util.Collections;
 import java.util.HashMap;
+import java.util.HashSet;
 import java.util.Iterator;
+import java.util.List;
 import java.util.Map;
+import java.util.Set;
 import java.util.UUID;
+import java.util.function.Consumer;
 
 import org.postgresql.core.Oid;
 import org.postgresql.jdbc.TypeInfoCache;
@@ -46,11 +50,47 @@ public class JdbcPostgresDialect extends PostgresDialect implements JdbcDialect
 
 	private static final JdbcPostgresArrayColumns ARRAY_COLUMNS = new JdbcPostgresArrayColumns();
 
+	private static final Set<Class<?>> SIMPLE_TYPES;
+
+	static {
+
+		Set<Class<?>> simpleTypes = new HashSet<>(PostgresDialect.INSTANCE.simpleTypes());
+		List<String> simpleTypeNames = Arrays.asList( //
+				"org.postgresql.util.PGobject", //
+				"org.postgresql.geometric.PGpoint", //
+				"org.postgresql.geometric.PGbox", //
+				"org.postgresql.geometric.PGcircle", //
+				"org.postgresql.geometric.PGline", //
+				"org.postgresql.geometric.PGpath", //
+				"org.postgresql.geometric.PGpolygon", //
+				"org.postgresql.geometric.PGlseg" //
+		);
+		simpleTypeNames.forEach(name -> ifClassPresent(name, simpleTypes::add));
+		SIMPLE_TYPES = Collections.unmodifiableSet(simpleTypes);
+	}
+
+	@Override
+	public Set<Class<?>> simpleTypes() {
+		return SIMPLE_TYPES;
+	}
+
 	@Override
 	public JdbcArrayColumns getArraySupport() {
 		return ARRAY_COLUMNS;
 	}
 
+	/**
+	 * If the class is present on the class path, invoke the specified consumer {@code action} with the class object,
+	 * otherwise do nothing.
+	 *
+	 * @param action block to be executed if a value is present.
+	 */
+	private static void ifClassPresent(String className, Consumer<Class<?>> action) {
+		if (ClassUtils.isPresent(className, PostgresDialect.class.getClassLoader())) {
+			action.accept(ClassUtils.resolveClassName(className, PostgresDialect.class.getClassLoader()));
+		}
+	}
+
 	static class JdbcPostgresArrayColumns implements JdbcArrayColumns {
 
 		private static final boolean TYPE_INFO_PRESENT = ClassUtils.isPresent("org.postgresql.jdbc.TypeInfoCache",

spring-data-r2dbc/src/main/java/org/springframework/data/r2dbc/dialect/PostgresDialect.java

@@ -2,18 +2,13 @@ package org.springframework.data.r2dbc.dialect;
 
 import io.r2dbc.postgresql.codec.Json;
 
-import java.net.InetAddress;
-import java.net.URI;
-import java.net.URL;
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.Collection;
 import java.util.Collections;
 import java.util.HashSet;
 import java.util.List;
-import java.util.Map;
 import java.util.Set;
-import java.util.UUID;
 import java.util.function.Consumer;
 import java.util.stream.Stream;
 
@@ -51,7 +46,7 @@ public class PostgresDialect extends org.springframework.data.relational.core.di
 	static {
 
 		Set<Class<?>> simpleTypes = new HashSet<>(
-				Arrays.asList(UUID.class, URL.class, URI.class, InetAddress.class, Map.class));
+				org.springframework.data.relational.core.dialect.PostgresDialect.INSTANCE.simpleTypes());
 
 		// conditional Postgres Geo support.
 		Stream.of("io.r2dbc.postgresql.codec.Box", //

spring-data-relational/src/main/java/org/springframework/data/relational/core/dialect/PostgresDialect.java

@@ -15,13 +15,15 @@
  */
 package org.springframework.data.relational.core.dialect;
 
-import java.util.Arrays;
+import java.net.InetAddress;
+import java.net.URI;
+import java.net.URL;
+import java.rmi.server.UID;
 import java.util.Collection;
 import java.util.Collections;
-import java.util.HashSet;
 import java.util.List;
+import java.util.Map;
 import java.util.Set;
-import java.util.function.Consumer;
 
 import org.springframework.data.relational.core.sql.Functions;
 import org.springframework.data.relational.core.sql.IdentifierProcessing;
@@ -32,7 +34,6 @@ import org.springframework.data.relational.core.sql.SQL;
 import org.springframework.data.relational.core.sql.SimpleFunction;
 import org.springframework.data.relational.core.sql.SqlIdentifier;
 import org.springframework.data.relational.core.sql.TableLike;
-import org.springframework.util.ClassUtils;
 
 /**
  * An SQL dialect for Postgres.
@@ -50,6 +51,9 @@ public class PostgresDialect extends AbstractDialect {
 	 */
 	public static final PostgresDialect INSTANCE = new PostgresDialect();
 
+	private static final Set<Class<?>> POSTGRES_SIMPLE_TYPES = Set.of(UID.class, URL.class, URI.class, InetAddress.class,
+			Map.class);
+
 	protected PostgresDialect() {}
 
 	private static final LimitClause LIMIT_CLAUSE = new LimitClause() {
@@ -152,32 +156,7 @@ public class PostgresDialect extends AbstractDialect {
 
 	@Override
 	public Set<Class<?>> simpleTypes() {
-
+		return POSTGRES_SIMPLE_TYPES;
-		Set<Class<?>> simpleTypes = new HashSet<>();
-		List<String> simpleTypeNames = Arrays.asList( //
-				"org.postgresql.util.PGobject", //
-				"org.postgresql.geometric.PGpoint", //
-				"org.postgresql.geometric.PGbox", //
-				"org.postgresql.geometric.PGcircle", //
-				"org.postgresql.geometric.PGline", //
-				"org.postgresql.geometric.PGpath", //
-				"org.postgresql.geometric.PGpolygon", //
-				"org.postgresql.geometric.PGlseg" //
-		);
-		simpleTypeNames.forEach(name -> ifClassPresent(name, simpleTypes::add));
-		return Collections.unmodifiableSet(simpleTypes);
-	}
-
-	/**
-	 * If the class is present on the class path, invoke the specified consumer {@code action} with the class object,
-	 * otherwise do nothing.
-	 *
-	 * @param action block to be executed if a value is present.
-	 */
-	private static void ifClassPresent(String className, Consumer<Class<?>> action) {
-		if (ClassUtils.isPresent(className, PostgresDialect.class.getClassLoader())) {
-			action.accept(ClassUtils.resolveClassName(className, PostgresDialect.class.getClassLoader()));
-		}
 	}
 
 	@Override