Database server to provide concurrent access for multiple clients to the database uses a shared cache for holding copy of the data being accessed

摘要

Multiple clients are given concurrent access to a database component stored on a database by a server which has a shared cache. The cache has a memory store coupled to the database that holds a copy of the database component. The memory store has a store gate that controls access to the store. The clients when accessing the memory store do so with their own client thread each of which includes a server component that communicates with the store gate and the client with respect to the database component. The database server may include a notify thread that detects changes to the database component and notifies the memory store gate of the change. The store gate may then notify the client server components which then notify the clients which are accessing the changed database component. The database server may include a lock manager which causes the memory store gate to prevent writes to the memory store by all but one of the clients when the one client is writing to the memory store.