Autovacuum execution takes a long time on my postgres9.4 instance, and my question is:

• Can I improve the speed of autovacuum by dropping the index? If I terminate the vacuum during the process, will its results take effect, as I may need to terminate the current vacuum before the drop index.
• Is there any other way to speed up autovacuum.

I’ve increased maintenance_work_mem, set vacuum_cost_limit to a higher value and set vacuum_cost_deplay to 0.

Any suggestion or help would by appriciated!