>
> Many thanks. Is this way correct? I am learning what is meant by 'top
> posting'.
>
Yes.
On the subject of your settings, I don't see anything for work_mem,
random_page_cost and other commonly tuned parameters. That would be a good
start. What sort of machine specs are there for Postgres instance? Cpu,
ram, disk type (spinning disk, ssd, etc)? Are any other applications
running on this machine?
Do you have an example query and explain analyze output? Are you aware of
https://explain.depesz.com/ ?