What's the difference between tscollect and collect? Is there any benefit to using tstats/tscollect or summary indexing over accelerated reporting? Also, what scenario is summary indexing better suited for than tstats/tscollect, and vice versa?
You probably want to go through the following page as it is extremely detailed: http://docs.splunk.com/Documentation/Splunk/6.3.2/Knowledge/Aboutsummaryindexing
Other useful links:
Hope that helps.