Data synchronization method and data synchronization system

The embodiment of the invention provides a data synchronization method and a data synchronization system. The method comprises the following steps: storing to-be-synchronized data into a memory database of a server, and generating an identifier of the to-be-synchronized data; and obtaining the identifier of the synchronized data of the client, and starting from the next identifier of the identifier of the synchronized data of the client, sending the corresponding to-be-synchronized data to the client. The non-persistent storage of the to-be-synchronized data with short time efficiency is realized by utilizing the memory database, so that the to-be-synchronized data is prevented from occupying a large amount of storage resources, and the waste of the storage resources is avoided. 本申请实施例提供了数据同步方法和数据同步系统。该方法包括：将待同步数据存入服务端的内存数据库中，并生成待同步数据的标识；获取客户端已同步数据的标识，从客户端已同步数据的标识的下一个标识开始，向客户端发送对应的待同步数据。利用内存数据库来实现短时效的待同步数据的非持久化存储，避免了待同步数据大量占用存储资源，避免了存储资源浪费。