HHH-18835 Use multi-table insert also for generators that don't support bulk inserts

Author: beikov

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

@@ -4819,10 +4819,11 @@ private boolean isSubselect() {
 
 	private boolean generatorNeedsMultiTableInsert() {
 		final var generator = getGenerator();
-		if ( generator instanceof BulkInsertionCapableIdentifierGenerator
+		if ( generator instanceof BulkInsertionCapableIdentifierGenerator bulkInsertionCapableGenerator
 				&& generator instanceof OptimizableGenerator optimizableGenerator ) {
 			final var optimizer = optimizableGenerator.getOptimizer();
-			return optimizer != null && optimizer.getIncrementSize() > 1;
+			return optimizer != null && optimizer.getIncrementSize() > 1
+				|| !bulkInsertionCapableGenerator.supportsBulkInsertionIdentifierGeneration();
 		}
 		else {
 			return false;

hibernate-core/src/main/java/org/hibernate/query/sqm/internal/SqmQueryImpl.java

@@ -625,10 +625,11 @@ private boolean useMultiTableInsert(EntityPersister persister, SqmInsertStatemen
 		boolean useMultiTableInsert = persister.hasMultipleTables();
 		if ( !useMultiTableInsert && !isSimpleValuesInsert( sqmInsert, persister ) ) {
 			final var identifierGenerator = persister.getGenerator();
-			if ( identifierGenerator instanceof BulkInsertionCapableIdentifierGenerator
+			if ( identifierGenerator instanceof BulkInsertionCapableIdentifierGenerator bulkInsertionCapableGenerator
 					&& identifierGenerator instanceof OptimizableGenerator optimizableGenerator ) {
 				final var optimizer = optimizableGenerator.getOptimizer();
-				if ( optimizer != null && optimizer.getIncrementSize() > 1 ) {
+				if ( optimizer != null && optimizer.getIncrementSize() > 1
+					|| !bulkInsertionCapableGenerator.supportsBulkInsertionIdentifierGeneration() ) {
 					useMultiTableInsert = !hasIdentifierAssigned( sqmInsert, persister );
 				}
 			}