How to maintain Azure SQL Indexes and Statistics

Hi cwalshe

rebuilding and reorganizing indexes as well as updating statistics with full scan is an intensive IO operation.

this can explain the high resource usage you can see. 

however, if this ran when the system is idle - this is good, and it uses as much resource as it can to finish the maintenance task. 

this is the reason for why we recommend to run the maintenance during night / weekend / system idle time. 

if that;s not possible we should be more granular with the maintenance or maybe use different time or different service tier. 

note that even if you see high resource usage that does not necessarily means that your application cannot work at the same time. 

it really depend on the workload. 

HTH, 

Yochanan.