FlexyPool VS HikariCP

However, PostgreSQL caches the sequences per-connection (different from Oracle that caches in the instance shared memory). Sequences can be a bottleneck in case of a storm where all have a cold cache, and here is a workaround. Note that re-connecting in PostgreSQL is expensive for many reasons and better fixt that with a connection pool that is not too dynamic (if you need this, you should have a look at FlexiPool)

FlexyPool

Looks like HikariCP is also awaiting fixes for this https://github.com/brettwooldridge/HikariCP/pull/2055

I have used hikari and exposed to do this in the past with postgres, although other dialects are supported.

I found one suggestion from the author of HikariCP on how to address this, which I implemented and it worked. However, there are additional classes involved, and it feels a little clunky and hard to follow.

Not really, you can change some things in spring boot but doing so will typically trigger a refresh which is less reliable than restarting but still causes a large performance hit. You could probably do it with hikari if you really needed to but it's inadvisable to build your application around this mechanic.

# https://github.com/brettwooldridge/HikariCP/wiki/About-Pool-Sizing

Not familiar with Python but this thread about a Java connection pool might be interesting: https://github.com/brettwooldridge/HikariCP/wiki/About-Pool-Sizing

Whatever you choose, presuming your app is database heavy, I highly recommend spending time on DB schema design to make all queries as short as possible, avoid relying on transactions, and keep your connection pool tiny. For reference: https://github.com/brettwooldridge/HikariCP/wiki/About-Pool-Sizing

You reminded me of the HikariCP library and it’s documentation: Clear and simple with references to other libraries trying to accomplish the same thing. It is not in the closure space though.

https://github.com/brettwooldridge/HikariCP