By themselves, neither DB Connect nor Universal Forwarder can tell you the performance of your database. OTOH, if your database server has the means to record its own performance metrics then either method can be used to get those metrics into Splunk. Use DB Connect if the metrics are stored in a table; use a UF if they're written to a text file.
Thanks for your response. Can you provide some more details of how to configure SQL server to record the SP performance including its execution time etc. so that Splunk can index the data. Are you taking something custom way to do this or there is a native way in SQL server to enable logging of this data?