Major Description
In DummyTxnManager, the lockMode for a WriteEntity (e.g. database, table) is determined by "complete" instead of its writeType. But since DDL output WriteEntity is usually complete, some DDL operations might be given exclusive locks which are actually not needed, which causes unnecessary locking contention. For example, in createTable, DummyTxnManager suggests an exclusive lock to table database writeentity since it is complete.
