On 2018-07-06 12:02:39 -0700, Joshua D. Drake wrote: > On 07/06/2018 11:57 AM, Andres Freund wrote: > > On 2018-07-06 14:49:53 -0400, Robert Haas wrote: > > > I think we also have to ask ourselves in general whether snapshots of > > > this data are worth what they cost. I don't think anyone would doubt > > > that a consistent snapshot of the data is better than an inconsistent > > > view of the data if the costs were equal. However, if we can avoid a > > > huge amount of memory usage and complexity on large systems with > > > hundreds of backends by ditching the snapshot requirement, then we > > > should ask ourselves how important we think the snapshot behavior > > > really is. > > Indeed. I don't think it's worthwhile major additional memory or code > > complexity in this situation. The likelihood of benefitting from more / > > better stats seems far higher than a more accurate view of the stats - > > which aren't particularly accurate themselves. They don't even survive > > crashes right now, so I don't think the current accuracy is very high. > > > Will stats, if we move toward the suggested changes be "less" accurate than > they are now? We already know that stats are generally not accurate but they > are close enough. If we move toward this change will it still be close > enough?
I don't think there's a meaningful difference to before. And at the same time less duplication / hardcoded structure will allow us to increase the amount of stats we keep. Greetings, Andres Freund
