Can we identified purge,analyze_statisitics or similar query run on which pool?

Try something like this if you know the transaction_id and statement_id:
select resource_pool from query_consumption
where
transaction_id = 72057594230919944 and statement_id = 1;

Or this if you don't:
select resource_pool from query_consumption
where
label = 'xyz';

I am using a 9.0.1 version. query_consumption table is not present.

It's from TM (Tuple Mover) pool. Try the below query
select * from system_services;