On Mon, 2008-06-02 at 11:59 -0400, Jignesh K. Shah wrote: > > Simon Riggs wrote: > > > > Some other problems I see with GUCs > > > > * It's not possible to set one parameter depending upon the setting of > > another. > > > > To me this is more critical.. Most people I have seen will increase one > or few but not all parameters related to memory which can result in loss > of performance and productivity in figuring out. > > What happened to AvailRAM setting and base all memory gucs on that. > Ideally PostgreSQL should only create one big memory pool and allow all > other variables to change runtime via dba or some tuner process or > customized application as long as total is less than the allocated > shared_memory and local_memory settings. (This will also reduce the need > of restarting Postgres if a value needs to be changed)
Agreed. Right now, we can't even do that in code, let alone in config file. If we had a smart_memory_config = on then we'd be able to say in the backend: if (smart_memory_config) { other_thing = 0.1 * Nbuffers; } but the GUCs are evaluated in alphabetical order, without any way of putting dependencies between them. So they are notionally orthogonal. -- Simon Riggs www.2ndQuadrant.com PostgreSQL Training, Services and Support -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers