The viability of Unix-based relational database systems in transaction processing applications is seen as such a key issue that Informix Software Inc has, as reported briefly, announced a money-back guarantee that its Informix-Turbo database will perform faster than any other database engine for new Unix-based transaction processing applications. The company reckons the performance monitoring and tuning facilities of the product are instrumental in ensuring that it is not like ly to have to make any refunds: it’s hard to imagine too many people developing versions of an application for more than one database manager at a time, even with the universal implementation of SQL, but Informix says this is a more tangible way to help users make a transaction processing decision than simply making claims based on benchmarks. The offer is available only until March 31,1989 and customers must inform Informix within 30 days of purchase that they are developing a transaction processing application and must complete the application by December 31 1989. And customers had better make sure that they have managed to get every drop of performance out of the product before complaining: Informix reserves the right to have a technical consultant analyse and fine-tune Informix performance before issuing the money-back guarantee, and may end up feeling they are suffering a sentence comparable with that of Sheherazade and her 1,001 Arabian Nights: Informix will charge consultancy fees if the product turns out to runs faster than another database manager as a result of the tuning.