Datawarehouse Star Data Collection job time taken reduced in 5.0.2

Hello,
I just completed a staging upgrade of CLM v.4.0.4 to v.5.0.2 Ifix22. I did not opt to install the DCC application. I am still using the same data collection method as the one used in v.4.0.4. Now, after running the post upgrade data collection jobs, I noticed that the time taken for the Star Data Collection job went from taking 4h+ to just 15 minutes. The Data Collection Job status page indicates that all jobs were completed successfully. What has changed in v.5.0.2. Is there an explanation for this drastic variance in the time taken.