In LMDB it is possible to use DbiFlags.MDB_INTEGERKEY when opening a database. When this flag is used then it is assumed that the keys are stored in native byte order.

When I have one database with MDB_INTEGERKEY then I use ByteBuffer.order(ByteOrder.nativeOrder()). Otherwise I keep the order.

When I retrieve values from the MDB_INTEGERKEY store I need to change the byte order of the returned ByteBuffer. Note that "db1" uses MDB_INTEGERKEY and "db2" not. The ByteBuffer which is returned is shared between both databases.

			try (Txn<ByteBuffer> txn = env.txnRead();) {
				ByteBuffer result = db1.get(txn, key); // <-- This buffer is re-used
				result.order(ByteOrder.nativeOrder());
				assertEquals(100, result.getInt());
			}
			try (Txn<ByteBuffer> txn = env.txnRead();) {
				ByteBuffer result = db2.get(txn, key);
				assertEquals(333, result.getInt()); // FAIL because "result" has native order
			}

The API does not mention that I cannot change e.g. the byte order of the returned ByteBuffer object.