A method includes determining a first node set and a second node set that are in a distributed database and that are separately associated with a first data table, where data in the first data table is stored in the first node set, migrating the data from the first node set to the second node set, receiving, in a process of migrating the data, a target service request for the first data table, determining, in response to the target service request, a third node set in the first node set and the second node set that is configured to respond to the target service request, and sending the target service request to a first data node in the third node set.