Craig Ringer wrote:
This is probably a stupid question, but: with PostgreSQL's use of shared memory, is it possible to load dictionaries into a small reserved shm area when the first backend starts, then use the preloaded copy in subsequent backends? That way the postmaster doesn't have to do any risky work. Anything that reduces backend startup costs and per-backend unshared memory would have to be a good thing. I've found it useful in the past to share resources with an mmap()ped file, too, especially if I want write protection from some or all processes. If the postmaster forked a process to generate the mmap()able compiled dictionary files on startup then it'd be pretty safe from any misbehaviour of the dictionary compiling process. Then again, I can't say I've personally noticed the cost of loading tsearch2 dictionaries.
So the dictionary will be parsed on the first usage by the given backend, and from that moment on, all running backends and all backends that will be spawned afterwards will have access to the parsed dictionary structures thanks to the shm?
That seems to solve all issues - speed, memory and updating. Would this be a way to go? Obviously, it might boil down to "write a patch", but if someone actually wrote a patch, would this approach be acceptable?
Thanks, Steve PS: Please, CC me, as I am off the list.
