From: Warren Young Date: April 25 2009 4:33pm Subject: Re: Limit of concurrent connections List-Archive: http://lists.mysql.com/plusplus/8532 Message-Id: MIME-Version: 1.0 (Apple Message framework v930.3) Content-Type: text/plain; charset=US-ASCII; format=flowed; delsp=yes Content-Transfer-Encoding: 7bit On Apr 25, 2009, at 5:59 AM, Martin Defeche wrote: > I'm working on three different programs that all uses the same > database and > have to run concurrently. In one of them I'm using 3 thread and I > use 2 > connections for each threads. The other programs use 3 connections. The only way to require more than one connection per thread is if each thread can process multiple overlapping queries. It's better to finish with one query per thread before starting a new one, requiring just one connection per thread at most. Processing multiple queries at once from a single thread ties up more resources on both sides of the connection. > Sould I use the connection pool for the program using 6 connection > or using > 9 connections is not too big ? As it says in the user manual, the connection pool works better than a connection per thread when you can't guarantee that a given thread will execute queries often enough to avoid server timeout problems. This can either be because some threads don't require constant access to a database connection, or because there can be long idle times in the application.