perf tuning for 28 cores and 252GB RAM

I am using a Postgres instance in an HPC cluster, where they have
generously given me an entire node. This means I have 28 cores and 252GB
RAM. I have to assume that the very conservative default settings for
things like buffers and max working memory are too small here.

We have about 20 billion rows in a single large table. The database is not
intended to run an application but rather to allow a few individuals to do
data analysis, so we can guarantee the number of concurrent queries will be
small, and that nothing else will need to use the server. Creating multiple
different indices on a few subsets of the columns will be needed to support
the kinds of queries we want.

What settings should be changed to maximize performance?

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Michael J. Curry