Your database connection options vary according to how the user is authenticated. If the world uses login authentication, you can specify the number of connections each user can have for each database. Connections are not pooled; each user gets a separate connection.
Typically, the number of connections for each data source used by a world is equal to the number of queries to any one data source that are executed simultaneously. Specifically, the number of connections you need for a particular data source is proportional to the following factors:
For example, if your packet size is the same as the maximum result set, and the most queries to a data source in a scene is five, you should have at least five connections. You might need more connections if your concurrent usage is high.