As a means of data storage the ELF system uses the modern relational database Firebird SQL.

Firebird (FirebirdSQL) – is a compact, cross-platform, free database management system (DBMS) that runs on GNU / Linux, Mac OS, Microsoft Windows and various Unix platforms. As the advantages of Firebird can be noted multi-version architecture that enables parallel processing of operational and analytical inquiries, compactness (the distribution 5Mb), high efficiency and powerful language support for stored procedures and triggers. Firebird performance is not inferior to many well-known commercial databases. More information about Firebird can be found in Wikipedia or materials on the Firebird site.

ELF system uses client-server technology, which has the following advantages:

•   Optimization of the load of a computing system between the server and the client part of the program.
•   Increased performance for read and data processing operations, as the server hardware is usually much more powerful.
•   All the data is stored on the server, which is generally much better protected then most of the customers. On the server it is easier to provide the authority control to allow access to data only to clients with appropriate access rights.
•   Allows to combine different clients. Clients with different hardware platforms, operating systems, etc. often can use the resources of one server

DBMS Firebird, can be deployed on systems UNIX / Linux, which can be considered an additional advantage because:

•   Linux and many UNIX-systems are free of charge;
•   Linux / UNIX systems are optimized for performance;
•   Linux / UNIX viruses are virus-free, hence their increased safety;
•   Systems Linux / UNIX are extremely reliable. Being configured once, they work for years.