When something related crops up several times in a few days you really start to wonder whats going on? In a conversation with a client regarding a ERP system upgrade we got to talking about the database it was written in and they were surprised when I knew what this database was.
PICK was used heavily in the health service when I worked there and was able to see it employed acros various mini computer plaforms from HP, IBM and Data General. It was used as a benchmarking tool and the existence of ports of PICK such as Universe and Unidata were mandatory for any supplier who offered their hardware for sale at that time.
Wikipedia gives a good explanation of the origins of PICK
The Pick operating system (often called just “the Pick system” or simply “Pick”) is a demand-paged, multiuser, virtual memory, time-sharing computer operating system based around a unique “multivalued” database. Pick is used primarily for business data processing. Though its use has never been properly advertised, its capabilities are far ahead of their time and there is still a strong enthusiastic user community[citation needed].
The term “Pick system” has also come to be used as the general name of all operating environments which employ this multivalued database and have some implementation of Pick/BASIC and ENGLISH/Access queries. Although Pick started on a variety of minicomputers, the system and its various implementations eventually spread to a large assortment of microcomputers, personal computers and mainframe computers and was still in use as of 2012[update].
In many ways its the multivalue aspect of it that has most interest to database architects since the argument is that the more complex the relationships become between normalised data then the more the “non sql” aspect of the non – Normal form design of the Pick data structures become a speed and complexity differentiator. It you wanted to get your hands dirty with PICK I found a link http://openqm.com/cgi/lbscgi.exe that will allow you to run a test environment.