yeah, I would like to have this data structure and would be able to access it from all forks / threads. In theory threads would be nice, but sadly the way they are currently implemented in perl (shared data are not really shared, everything is damn slow) make them close to useless for us :(
I am afraid I have to accept that these (for us uneccesary) write do happen and that we can not really avoid them. I am currently thinking of how we could rewrite the whole application to get the needed data from somewhere else (some suggested a in memory database) without taking a too large performance hit.