Since I recently stumbled over issues with persistent connections I got reminded once again about SQL Relay. Not really a solution to my problems, since SQL Relay will not magically clean up open transactions (or does it?). However it would help reduce the number of open connections while still getting rid of most the connection overhead. Then again at peak times it might not reduce the number of connections all that much and at low traffic times I guess the main benefit is that one can have more spare children hanging around without clogging up the DB with lots of open connections.
Still this makes me wonder if its even worth it, as I am not sure how much it will really safe me at high load times, as at least in my current app it seems impossible to get even a single request that does not have to hit the DB. So maybe SQL Relay is more useful for apps where not every request needs a DB connection or where the DB connection is not needed for a larger chunk of the request and so the connection can be returned to the SQL Relay pool.
More annoyingly it seems that there is no PDO driver yet, but just an odd API "native" extension. Worse yet it all seems to be GPL'ed, which makes it impossible to get into PECL and as a result it will probably never get out of its niche in the PHP community. So anyone played with it and give me some feedback on of its worth to dive in or if you agree that an application that needs to talk to the database for the most part while handling a request is not going to benefit?
I have used in some situations where oracle was needed and there were some problems using native php oracle extension (like connections died randomly = etc.). It's working quite good for some years now but sometimes there are problems that on server startup sqlrelay does not open connections on starting up service. Had no other problems.
I hear reports evenly split about SQL Relay. The reasons for large Oracle sites to evaluate it are weakening. OCI8 1.3 now supports native connection pooling (with Oracle 11g). And OCI8 is of course stabler since it was refactored a few years back.
Do you have an idea if it's possible to support SQL Relay by Doctrine?
I think the problem is that no PHP AL supports it. So it is nearly impossible to evaluate it if you don't want to code everything by hand..
Are the adapters around the "native" extensions still working? If so it should be entirely possible to write an adapter around the SQL Relay PHP API. I think the bigger issue with being able to try it out is that the API is not part of pecl.php.net, which it cannot due to its license.