Trending @Infosys; Backup technologies - Dell EMC

Anyone here with knowledge in the Backup Technologies? More into:

1. Dell EMC Avamar
2. PPDM
3. Netbackup

Dell EMC Data domain

I just wanted to know the solution for the issues,

1. Avamar - Backup scheduled daily at 9pm est, but this backup runs till next day & another backup with the same server & policy is in waiting in queue. So daily I'm cancelling manually. Any solution to resolve it?
2. PPDM - Indexing is for what?? Is indexing required or without that also restoration is possible? In my case, the indexing job is staying in queue for longer days, running for longer days, and failing as it will be retired in 2 hours.
3. DATA DOMAIN - important concepts to civer