Electronic arrangement for use in enriching data stream with subscriber information in a communications network preferably comprising a mobile network, the arrangement comprising at least one data interface for transferring data, at least one memory for storing instructions and other data, and at least one controller for processing instructions and other data, said at least one controller being configured, in accordance with the stored instructions, to cause storing same data in a relational database, such as SQL database, preferably including subscriber related profile data, and in a non-relational, preferably in-memory, database; wherein responsive to receipt of a data write request, optionally from a network entity, BSS/OSS system or other external system, triggering data write in a single transaction incorporating data write into the relational database and replication into the non-relational database, wherein in the case of a failure having regard to the replication into the non-relational database, the at least one controller is further configured to execute an exception procedure; and responsive to receipt of a data retrieval query from a requestor, optionally from said network or other entity processing a data stream, and dependent on the type of the query, fetching data from the non-relational database or relational database, and returning it to the requestor or other selected target. Related method is presented.