Top-level requirements T1-T10 imply a flexible DBMS with distributed processing/storage for data capacity and fast response times. Requirements C6, D3, D4, D13 (explicitly) and D14 require DBMS `federation' of source catalogues and flexibility in schema design. Requirement D6 explicitly requires a DBMS that has an implementation of extensible SQL-like querying (see later). Overall, the requirements imply a commercial DBMS along with an operating system capable of implementation on high aggregate IO hardware, probably a distributed storage system. This in turn implies some degree of software parallelisation.