"Model" database size is read by transfer when not creating a database.

When using the Transfer object to clone a database catalog into an existing empty database, DataTransferBase invokes SetTargetServerInfoAndGetModelSize() and reads the size of the "model" database. This is unnecessary and actually unwanted due to the fact that this seems to place an exclusive lock on the "model" database.

从 Transfer 流程开始，跟踪 DataTransferBase 对 SetTargetServerInfoAndGetModelSize() 的调用。确认克隆到现有的空数据库时为何会读取模型数据库，以及这是否会产生不必要的排他锁。Issue 未指定源文件或测试；完成标准是此场景中不再发生不必要的模型大小读取。