On 14 June 2015 at 23:51, Tomas Vondra <tomas.von...@2ndquadrant.com> wrote:
> The current state, where HashAgg just blows up the memory, is just not >>> reasonable, and we need to track the memory to fix that problem. >>> >> >> Meh. HashAgg could track its memory usage without loading the entire >> system with a penalty. >> > > +1 to a solution like that, although I don't think that's doable without > digging the info from memory contexts somehow. > >> Jeff is right, we desperately need a solution and this is the place to start. Tom's concern remains valid: we must not load the entire system with a penalty. The only questions I have are: * If the memory allocations adapt to the usage pattern, then we expect to see few memory chunk allocations. Why are we expecting "the entire system" to experience a penalty? * If we do not manage our resources, how are we certain this does not induce a penalty? Not tracking memory could be worse than tracking it. -- Simon Riggs http://www.2ndQuadrant.com/ <http://www.2ndquadrant.com/> PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services
