N1QL query to fetch the records is taking longer time

I am trying to use a query to fetch all the records in DB without any indexes, like below

select * from bucket where _class=“com.myname.domain.Student”;

the DB of 13k records is nearly taking 60 seconds to fetch the records in couchbase workbench, how can i improve the performance for select query to fetch all the records in DB?

CREATE INDEX ix1 ON bucket(_class);
FROM bucket WHERE _class="com.myname.domain.Student";


I have tried the indexing and executed the query, for a bucket with 12.3k records, i could get the output in 40s, with select query that fetches entire data set , is there any way i can immprove the performance to fetch all the records at a time with minimal execution time?

As you see plan IN/OUT count those are same that means it more efficient plan.
Only option you have user covered index below get all keys and use SDKs Reactive API get the full documents

FROM bucket WHERE _class="com.myname.domain.Student";