The invention addresses the access to subscriber data in a telecommunication system, and provides for a database system with a master database and with a plurality of slave databases acting as memory caches closely located with the requester applications and for a method of handling such database system. The method includes the steps of: 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.