A first cluster and a second cluster include at least one single-threaded main controller, the at least one single-threaded main controller processes one access request requesting for data at a time, and the data accessed by the access request is jointly managed by the first cluster and the second cluster. A database server determines hot data managed by the first cluster and determines whether a migration condition for migrating the hot data to the second cluster is met. The second cluster manages hot data that meets the migration condition. The database server migrates the hot data that meets the migration condition to the second cluster and triggers an update of an access path of the hot data.