> How would you batch this in postgres and get any value? You can nest them all in a single transaction. But, because they are interactive transactions that doesn't reduce your number of network hops.

you can write it as stored procedure in your favorite language, or use domain socket where communication happens using through shared memory buffs without network involved.

In your post, I think big performance hit for postgres potentially comes from focus on update only statement, in SQlite updates likely happen in place, while postgress creates separate record on disk for each updated record, or maybe some other internal stuff going on.

Your benchmark is very simplistic, it is hard to tell what would be behavior of SQlite if you switch to inserts for example, or many writers which compete for the same record, or transaction would be longer. Industry built various benchmarks for this, tpc for example.

Also, if you want readers understand your posts better, you can consider using less exotic language in the future. Its hard to read what is and how is batched there.