q)datacenter: ([] name: `newyork`london`tokyo; webservers: 7 4 2); q)plan::update backends: webservers * 10 from datacenter q)webservers::select name, c

q)datacenter: ([] name: `newyork`london`tokyo; webservers: 7 4 2); q)plan::update backends: webservers * 10 from datacenter q)webservers::select name, cmdline:`:/usr/bin/webserver, instances:webservers from plan q)backends::select name, cmdline:`:/usr/bin/backend, instances:backends from plan q)1@.j.j backends; [{"name":"newyork","cmdline":":/usr/bin/backend","instances":70}, {"name":"london","cmdline":":/usr/bin/backend","instances":40}, {"name":"tokyo","cmdline":":/usr/bin/backend","instances":20}] kdb views track dependencies, so we can get Seattle represented with minimum effort: q)`datacenter insert (`seattle; 6); q)1@.j.j backends; [{"name":"newyork","cmdline":":/usr/bin/backend","instances":70}, {"name":"london","cmdline":":/usr/bin/backend","instances":40}, {"name":"tokyo","cmdline":":/usr/bin/backend","instances":20}, {"name":"seattle","cmdline":":/usr/bin/backend","instances":60}] What was "B" supposed to be twice of "A"? q)A:([] x:10?10); q)B::update x:x*2 from A q)A`x 8 1 9 5 4 6 6 1 8 5 q)B`x 16 2 18 10 8 12 12 2 16 10 q)update x:10?10 from `A; q)A`x 4 9 2 7 0 1 9 2 1 8 q)B`x 8 18 4 14 0 2 18 4 2 16 And the syntax is much nicer than JavaScript.