On Sat, Apr 17, 2021 at 1:58 PM PegoraroF10 <mar...@f10.com.br> wrote: > This long explaining was only to show, at least for me, that would be > desirable to have an additional information when Postgres is waiting for a > file. What if DataFileRead showing relfilenode it´s waiting for ?
I agree that this would be nice, but it's pretty much impossible to do it without adding quite a bit more overhead than the current system has. And it already has enough overhead to make Andres at least slightly grumpy, though admittedly a lot of things have enough overhead to make Andres grumpy, because he REALLY likes it when things go fast. :-) I suspect it's best to investigate problems like the one you're having using a tool like strace, which can provide way more detail than we could ever cram into a wait event, like the data actually read or written, timestamps for every operation, etc. But I also kind of wonder whether it really matters. If your system is getting stuck in a DataFileRead event for a long period of time, and assuming that's for real and not just some kind of reporting bug, it sounds a lot like you have a bad disk or a severely overloaded I/O subsystem. Because what else would lead to the system getting stuck inside read() for a long time? -- Robert Haas EDB: http://www.enterprisedb.com
