Oracle Corporation

Oracle sells database software that executes filtering and sorting operations directly inside its Exadata storage servers, using a proprietary protocol that links its SQL optimizer to those servers in a way no competing product can replicate. Because that filtering happens at the storage layer before any data moves to the processing layer, queries run faster than on standard database architectures — but only when Oracle's optimizer, storage cell software, and interconnect protocol are all present together, which means swapping out any one piece destroys the performance advantage. Over years of use, customers write that coupling into their own application code through PL/SQL stored procedures, Oracle Forms applications, and Database Link connections that tie multiple Oracle databases across a company into a single interlocked system. By the time a customer considers leaving, the exit cost is not a licensing fee but a full rewrite of that application code using migration tools that do not yet exist, which is why the annual support subscription — set at 22% of the licence price — renews without negotiation.