I have list of student exam detail in Couchbase bucket. Now I have to fetch student list grouped by their class and sum of each subject and total

Question

I have done this using query but as I have a large amount of data it takes more time. Now I have to pick the data in lesser time using design documents or Indexes. Kindly suggest which will be more efficient and execute with sorter time?

Here is an example:

[{"name":"alex","class":2,"english":59,"maths":50,"science":70},
{"name":"ave","class":3,"english":59,"maths":50,"science":70},
{"name":"dany","class":2,"english":59,"maths":50,"science":70}]

Excepted result:

[{"class":2,"english":118,"maths":100,"science":140},
{"class":3,"english":59,"maths":50,"science":70}]

Please give me a better solution to solve this with sample code.