> OK I admit it, I am a postgresql newbie. The developers FAQ says the
> postgresql "backend" is not multi-threaded. How serious is this?
Not serious at all... PostgreSQL is not multi-threaded, but it does take
advantage of multiple processes. Each connection spawns a new backend
process that run concurrently with other backend processes.
> If this means only one transaction at a time can make progress or the
> entire DBMS server is blocked on every disk I/O then that is very bad.
One transaction per connection. But you can have quite a large number of
connections, each with their own process.
> But if every connection gets its own backend, and the backends can run
> in parallel then not being multithreaded is no big deal.
Exactly.
> Here is the bottom line. Our app runs on multiple machines (we call
> them sinks) hitting one DBMS server for data. We expect the sinks to
> be able to all make progress at the same time. Each sink fetchs
> some data, goes compute bound for .2 to .4 seconds, and then
> sends a bunch of INSERT/UPDATE/DELETE to the DBMS.
> Will our sinks be able to run concurrently?
Yes, breathe easy :)
Greg
