On Wed, 2023-06-21 at 18:53 -0700, Wells Oliver wrote: > Hi all. Trying to asses our WAL checkpoint during heavy ETL loads. > Checkpoint timer is at 5min and it seems to be constantly checkpointing, maybe that's OK. > We see an increased % of buffer percentages in the logs during the checkpoint. Here's a run: > > [...] > > I don't want to read too much into it But that's how you learn... > but I am trying to understand it better to consider any potential changes in max WAL sizes, > or increasing our checkpoint timeouts if they are causing the ETL stuff to be slower than > it should. Our wal_level is currently set to logical but we plan to change this to replica > soon as it feels like overkill. You should increase "max_wal_size" until most of your checkpoints are triggered by timeout, once every 5 minutes. That will reduce the amount of WAL, because you will have fewer full-page images, and you will avoid redundant buffer writes. The only negative side effect is that recovery can take longer if you crash while loading. Yours, Laurenz Albe
