On Fri, Jun 14, 2019 at 5:43 PM Stephen Frost <sfrost@snowman.net> wrote:
The time information is all there and it tells you what it's doing and how much had to be done... If you're unhappy with how long it takes to write out gigabytes of data and fsync hundreds of files, talk to your storage people...
Right, but true only because they were "checkpoint starting: immediate". Otherwise the reported write time includes intentional sleeps added to honor the checkpoint_completion_target. A bit confusing to report it that way, I think.
I am the storage people too :)
So, what did you say to yourself? Have you done fundamental benchmarking at the OS level, to see how fast you can write out 1-2 GB of data changes spread out randomly over a few hundred GB of data, when it is not coming from PostgreSQL?