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copied!<p>I'm not sure I can answer your specific question, but wanted to suggest that global / singleton connection objects may not be the best idea if this if for a web-based system. DBMSs are generally designed to manage large numbers of unique connections in an efficient manner. If you are using a global connection object, then you are doing a couple of things:</p> <ol> <li><p>Forcing you pages to do all database connections sequentially and killing any attempts at asyncronous page loads. </p></li> <li><p>Potentially holding open locks on database elements longer than necessary, slowing down overall database performance.</p></li> <li><p>Maxing out the total number of simultaneous connections your database can support and blocking new users from accessing the resources.</p></li> </ol> <p>I am sure there are other potential consequences as well. Remember, this method will attempt to sustain a database connection for every user accessing the site. If you only have one or two users, not a problem. If this is a public website and you want traffic then scalability will become an issue.</p> <p><strong>[EDIT]</strong></p> <p>In larger scaled situations, creating new connections everytime you hit the datase can be bad. However, the answer is not to create a global connection and reuse it for everything. The answer is connection pooling. </p> <p>With connection pooling, a number of distinct connections are maintained. When a connection is required by the application the first available connection from the pool is retrieved and then returned to the pool once its job is done. If a connection is requested and none are available one of two things will happen: a) if the maximum number of allowed connection is not reached, a new connection is opened, or b) the application is forced to wait for a connection to become available.</p> <p><strong>Note:</strong> In .Net languages, connection pooling is handled by the ADO.Net objects by default (the connection string sets all the required information). </p> <p>Thanks to Crad for commenting on this.</p>

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