Why changing RDS aurora postgres from a db.t4g.medium (2vcpu) to a db.r6g.xlarge (4vcpu) descrease the number of commited transactions?

hello,

I understand that you changed number of vcpu , from 2vcpu to 4vcpu, but you see a decrease on number of commits. please correct me if i misunderstood you.

I can see from the screenshot, you are using too much cpu which is good. but the number of commits is purely your workload. so meaning that's the amount of workload you pushed to your database, you control that, remember that is just a counter like calls that are been made to desk

Note that you are the only one who can decrease the number of commit transaction. For more information about db.Transactions.xact_commit.avg please refer to this link[1]

I hope i was able to help you.

Reference link

1.https://docs.aws.amazon.com/AmazonRDS/latest/UserGuide/USER_PerfInsights.UsingDashboard.Components.html#USER_PerfInsights.UsingDashboard.Components.Countermetrics