HHH-14238 Option to include collection fields in the default fetch group

There is no good reason to lazily-instantiate a collection
wrapper, since that operation never requires access to the
database.

See discussion here:

   https://github.com/hibernate/hibernate-reactive/issues/374

hibernate-core/src/main/java/org/hibernate/boot/internal/SessionFactoryOptionsBuilder.java

@@ -198,6 +198,7 @@ public class SessionFactoryOptionsBuilder implements SessionFactoryOptions {
 	private boolean orderInsertsEnabled;
 	private boolean postInsertIdentifierDelayed;
 	private boolean enhancementAsProxyEnabled;
+	private boolean collectionsInDefaultFetchGroupEnabled;
 
 	// JPA callbacks
 	private boolean callbacksEnabled;
@@ -1067,6 +1068,11 @@ public class SessionFactoryOptionsBuilder implements SessionFactoryOptions {
 		return enhancementAsProxyEnabled;
 	}
 
+	@Override
+	public boolean isCollectionsInDefaultFetchGroupEnabled() {
+		return collectionsInDefaultFetchGroupEnabled;
+	}
+
 	@Override
 	public boolean isOmitJoinOfSuperclassTablesEnabled() {
 		return omitJoinOfSuperclassTablesEnabled;
@@ -1359,6 +1365,10 @@ public class SessionFactoryOptionsBuilder implements SessionFactoryOptions {
 		mutableJpaCompliance().setCachingCompliance( enabled );
 	}
 
+	public void enableCollectionInDefaultFetchGroup(boolean enabled) {
+		this.collectionsInDefaultFetchGroupEnabled = enabled;
+	}
+
 	public void disableRefreshDetachedEntity() {
 		this.allowRefreshDetachedEntity = false;
 	}

hibernate-core/src/main/java/org/hibernate/boot/spi/AbstractDelegatingSessionFactoryOptions.java

@@ -448,6 +448,11 @@ public class AbstractDelegatingSessionFactoryOptions implements SessionFactoryOp
 		return delegate.isEnhancementAsProxyEnabled();
 	}
 
+	@Override
+	public boolean isCollectionsInDefaultFetchGroupEnabled() {
+		return delegate.isCollectionsInDefaultFetchGroupEnabled();
+	}
+
 	@Override
 	public boolean isOmitJoinOfSuperclassTablesEnabled() {
 		return delegate.isOmitJoinOfSuperclassTablesEnabled();

hibernate-core/src/main/java/org/hibernate/boot/spi/SessionFactoryOptions.java

@@ -315,5 +315,9 @@ public interface SessionFactoryOptions {
 		return false;
 	}
 
+	default boolean isCollectionsInDefaultFetchGroupEnabled() {
+		return false;
+	}
+
 	boolean isOmitJoinOfSuperclassTablesEnabled();
 }

hibernate-core/src/main/java/org/hibernate/bytecode/enhance/spi/interceptor/EnhancementHelper.java

@@ -15,6 +15,7 @@ import org.hibernate.bytecode.BytecodeLogger;
 import org.hibernate.engine.spi.SessionFactoryImplementor;
 import org.hibernate.engine.spi.SharedSessionContractImplementor;
 import org.hibernate.internal.SessionFactoryRegistry;
+import org.hibernate.mapping.Collection;
 import org.hibernate.mapping.OneToOne;
 import org.hibernate.mapping.Property;
 import org.hibernate.mapping.ToOne;
@@ -30,7 +31,8 @@ public class EnhancementHelper {
 	public static boolean includeInBaseFetchGroup(
 			Property bootMapping,
 			boolean isEnhanced,
-			boolean allowEnhancementAsProxy) {
+			boolean allowEnhancementAsProxy,
+			boolean collectionsInDefaultFetchGroupEnabled) {
 		final Value value = bootMapping.getValue();
 
 		if ( ! isEnhanced ) {
@@ -63,7 +65,8 @@ public class EnhancementHelper {
 			return true;
 		}
 
-		return ! bootMapping.isLazy();
+		return collectionsInDefaultFetchGroupEnabled && ( value instanceof Collection )
+				|| ! bootMapping.isLazy();
 	}
 
 	public static <T> T performWork(

hibernate-core/src/main/java/org/hibernate/bytecode/enhance/spi/interceptor/LazyAttributesMetadata.java

@@ -34,7 +34,8 @@ public class LazyAttributesMetadata implements Serializable {
 	public static LazyAttributesMetadata from(
 			PersistentClass mappedEntity,
 			boolean isEnhanced,
-			boolean allowEnhancementAsProxy) {
+			boolean allowEnhancementAsProxy,
+			boolean collectionsInDefaultFetchGroupEnabled) {
 		final Map<String, LazyAttributeDescriptor> lazyAttributeDescriptorMap = new LinkedHashMap<>();
 		final Map<String, Set<String>> fetchGroupToAttributesMap = new HashMap<>();
 
@@ -47,7 +48,8 @@ public class LazyAttributesMetadata implements Serializable {
 			final boolean lazy = ! EnhancementHelper.includeInBaseFetchGroup(
 					property,
 					isEnhanced,
-					allowEnhancementAsProxy
+					allowEnhancementAsProxy,
+					collectionsInDefaultFetchGroupEnabled
 			);
 			if ( lazy ) {
 				final LazyAttributeDescriptor lazyAttributeDescriptor = LazyAttributeDescriptor.from( property, i, x++ );

hibernate-core/src/main/java/org/hibernate/persister/entity/AbstractEntityPersister.java

@@ -37,6 +37,7 @@ import org.hibernate.QueryException;
 import org.hibernate.Session;
 import org.hibernate.StaleObjectStateException;
 import org.hibernate.StaleStateException;
+import org.hibernate.boot.spi.SessionFactoryOptions;
 import org.hibernate.bytecode.enhance.spi.LazyPropertyInitializer;
 import org.hibernate.bytecode.enhance.spi.interceptor.BytecodeLazyAttributeInterceptor;
 import org.hibernate.bytecode.enhance.spi.interceptor.EnhancementAsProxyLazinessInterceptor;
@@ -586,7 +587,9 @@ public abstract class AbstractEntityPersister
 
 		this.navigableRole = new NavigableRole( persistentClass.getEntityName() );
 
-		if ( creationContext.getSessionFactory().getSessionFactoryOptions().isSecondLevelCacheEnabled() ) {
+		SessionFactoryOptions sessionFactoryOptions = creationContext.getSessionFactory().getSessionFactoryOptions();
+
+		if ( sessionFactoryOptions.isSecondLevelCacheEnabled() ) {
 			this.canWriteToCache = determineCanWriteToCache( persistentClass, cacheAccessStrategy );
 			this.canReadFromCache = determineCanReadFromCache( persistentClass, cacheAccessStrategy );
 			this.cacheAccessStrategy = cacheAccessStrategy;
@@ -737,7 +740,8 @@ public abstract class AbstractEntityPersister
 			final boolean lazy = ! EnhancementHelper.includeInBaseFetchGroup(
 					prop,
 					entityMetamodel.isInstrumented(),
-					creationContext.getSessionFactory().getSessionFactoryOptions().isEnhancementAsProxyEnabled()
+					sessionFactoryOptions.isEnhancementAsProxyEnabled(),
+					sessionFactoryOptions.isCollectionsInDefaultFetchGroupEnabled()
 			);
 
 			if ( lazy ) {
@@ -813,7 +817,8 @@ public abstract class AbstractEntityPersister
 			final boolean lazy = ! EnhancementHelper.includeInBaseFetchGroup(
 					prop,
 					entityMetamodel.isInstrumented(),
-					creationContext.getSessionFactory().getSessionFactoryOptions().isEnhancementAsProxyEnabled()
+					sessionFactoryOptions.isEnhancementAsProxyEnabled(),
+					sessionFactoryOptions.isCollectionsInDefaultFetchGroupEnabled()
 			);
 			while ( colIter.hasNext() ) {
 				Selectable thing = (Selectable) colIter.next();
@@ -924,7 +929,7 @@ public abstract class AbstractEntityPersister
 
 		this.cacheEntryHelper = buildCacheEntryHelper();
 
-		if ( creationContext.getSessionFactory().getSessionFactoryOptions().isSecondLevelCacheEnabled() ) {
+		if ( sessionFactoryOptions.isSecondLevelCacheEnabled() ) {
 			this.invalidateCache = canWriteToCache && determineWhetherToInvalidateCache( persistentClass, creationContext );
 		}
 		else {

hibernate-core/src/main/java/org/hibernate/tuple/PropertyFactory.java

@@ -10,6 +10,7 @@ import java.lang.reflect.Constructor;
 
 import org.hibernate.EntityMode;
 import org.hibernate.HibernateException;
+import org.hibernate.boot.spi.SessionFactoryOptions;
 import org.hibernate.bytecode.enhance.spi.interceptor.EnhancementHelper;
 import org.hibernate.engine.internal.UnsavedValueFactory;
 import org.hibernate.engine.spi.IdentifierValue;
@@ -169,10 +170,12 @@ public final class PropertyFactory {
 		boolean alwaysDirtyCheck = type.isAssociationType() &&
 				( (AssociationType) type ).isAlwaysDirtyChecked();
 
+		SessionFactoryOptions sessionFactoryOptions = sessionFactory.getSessionFactoryOptions();
 		final boolean lazy = ! EnhancementHelper.includeInBaseFetchGroup(
 				property,
 				lazyAvailable,
-				sessionFactory.getSessionFactoryOptions().isEnhancementAsProxyEnabled()
+				sessionFactoryOptions.isEnhancementAsProxyEnabled(),
+				sessionFactoryOptions.isCollectionsInDefaultFetchGroupEnabled()
 		);
 
 		switch ( nature ) {

hibernate-core/src/main/java/org/hibernate/tuple/entity/BytecodeEnhancementMetadataPojoImpl.java

@@ -38,11 +38,12 @@ public final class BytecodeEnhancementMetadataPojoImpl implements BytecodeEnhanc
 			PersistentClass persistentClass,
 			Set<String> identifierAttributeNames,
 			CompositeType nonAggregatedCidMapper,
-			boolean allowEnhancementAsProxy) {
+			boolean allowEnhancementAsProxy,
+			boolean collectionsInDefaultFetchGroupEnabled) {
 		final Class mappedClass = persistentClass.getMappedClass();
 		final boolean enhancedForLazyLoading = PersistentAttributeInterceptable.class.isAssignableFrom( mappedClass );
 		final LazyAttributesMetadata lazyAttributesMetadata = enhancedForLazyLoading
-				? LazyAttributesMetadata.from( persistentClass, true, allowEnhancementAsProxy )
+				? LazyAttributesMetadata.from( persistentClass, true, allowEnhancementAsProxy, collectionsInDefaultFetchGroupEnabled )
 				: LazyAttributesMetadata.nonEnhanced( persistentClass.getEntityName() );
 
 		return new BytecodeEnhancementMetadataPojoImpl(

hibernate-core/src/main/java/org/hibernate/tuple/entity/EntityMetamodel.java

@@ -19,6 +19,7 @@ import java.util.Set;
 import org.hibernate.EntityMode;
 import org.hibernate.HibernateException;
 import org.hibernate.MappingException;
+import org.hibernate.boot.spi.SessionFactoryOptions;
 import org.hibernate.bytecode.enhance.spi.interceptor.EnhancementHelper;
 import org.hibernate.bytecode.spi.BytecodeEnhancementMetadata;
 import org.hibernate.cfg.NotYetImplementedException;
@@ -140,6 +141,8 @@ public class EntityMetamodel implements Serializable {
 
 		versioned = persistentClass.isVersioned();
 
+		SessionFactoryOptions sessionFactoryOptions = sessionFactory.getSessionFactoryOptions();
+
 		if ( persistentClass.hasPojoRepresentation() ) {
 			final Component identifierMapperComponent = persistentClass.getIdentifierMapper();
 			final CompositeType nonAggregatedCidMapper;
@@ -163,7 +166,8 @@ public class EntityMetamodel implements Serializable {
 					persistentClass,
 					idAttributeNames,
 					nonAggregatedCidMapper,
-					sessionFactory.getSessionFactoryOptions().isEnhancementAsProxyEnabled()
+					sessionFactoryOptions.isEnhancementAsProxyEnabled(),
+					sessionFactoryOptions.isCollectionsInDefaultFetchGroupEnabled()
 			);
 		}
 		else {
@@ -245,7 +249,8 @@ public class EntityMetamodel implements Serializable {
 			boolean lazy = ! EnhancementHelper.includeInBaseFetchGroup(
 					prop,
 					bytecodeEnhancementMetadata.isEnhancedForLazyLoading(),
-					sessionFactory.getSessionFactoryOptions().isEnhancementAsProxyEnabled()
+					sessionFactoryOptions.isEnhancementAsProxyEnabled(),
+					sessionFactoryOptions.isCollectionsInDefaultFetchGroupEnabled()
 			);
 
 			if ( lazy ) {
@@ -407,7 +412,7 @@ public class EntityMetamodel implements Serializable {
 		}
 
 		entityMode = persistentClass.hasPojoRepresentation() ? EntityMode.POJO : EntityMode.MAP;
-		final EntityTuplizerFactory entityTuplizerFactory = sessionFactory.getSessionFactoryOptions().getEntityTuplizerFactory();
+		final EntityTuplizerFactory entityTuplizerFactory = sessionFactoryOptions.getEntityTuplizerFactory();
 		final String tuplizerClassName = persistentClass.getTuplizerImplClassName( entityMode );
 		if ( tuplizerClassName == null ) {
 			entityTuplizer = entityTuplizerFactory.constructDefaultTuplizer( entityMode, this, persistentClass );