On 8 Prosinec 2011, 17:11, Marc Cousin wrote: > Le Thu, 8 Dec 2011 09:29:28 -0600, >> >> > - admission control, queuing and resource limiting to optimally >> >> > load a machine. Some limited level is possible with external >> >> > pooling, but only by limiting concurrent workers. >> > >> > Oracle has natively two ways of handling inbound connections: >> > - Dedicated, which is very similar to the PostgreSQL way of >> > accepting connections: accept(), fork() and so on >> > - Shared, which is based on processes listening and handling the >> > connections (called dispatchers) and processes doing the real work >> > (called workers, obviously). All of this works internally with >> > some sort of queuing and storing results in shared memory (I don't >> > remember the details of it) >> > >> > The advantage of this second architecture being of course that you >> > can't have more than N workers hitting your database >> > simultaneously. So it's easier to keep the load on the server to a >> > reasonable value. >> >> you have a couple of very good options to achieve the same in postgres >> -- pgbouncer, pgpool. >> > > I wish it was the same (I use and like both pgbouncer and pgpool too, > and they do a good job, I'm not arguing on that). But unfortunately it > isn't: you still have the notion of session for each connected client > in Oracle when using the shared servers model. True, it is not exactly the same, it's similar. I don't think PostgreSQL will ever provide 'shared backends' the way Oracle does - it would require significant code change. Most of the benefits can be achieved by using a connection pool without the added complexity. > It means you keep your session variables, your prepared statements, > your running transaction, etc… in each individual session while having > the multiplexing equivalent of a 'statement level' from pgbouncer. Yes. But if you expect that PostgreSQL will mimic Oracle architecture, then you're mistaken. It's simply a different solution with different architecture, and that means you may need to use different application design sometimes. Tomas -- Sent via pgsql-general mailing list (pgsql-general@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general
