Method and system for accessing subscriber data in a telecommunication system, and providing a database system with a master database and slave databases acting as memory caches located with requester applications. The method including: configuring data clusters at the master database, each data cluster identifying subscriber data associated with an operation and assigned a priority; determining at the master database the priority of the data cluster associated with a received operation; and either providing the data cluster associated with the operation from the master database towards the slave database, replicating the received data cluster at the slave database, and executing the operation with the received data cluster at the slave database, where the priority of the data cluster is higher than for previous operations; or executing the operation with the data cluster at the master database, where the priority of the data cluster is lower than for a previous operation.