Possibly Go code issue or ES?

[fading plume]

Hello. This might be related to GO. Yes I know that the versions sucks, but here I go. Stack is ElasticSearch 1.7. I encountered a problem where simple network request gets heavy, it takes from 5 - 15 seconds to complete even though the response is not big. I have found out that it is because of ES query that is looking through ~25 million indexed data to get 50 items from the whole response. I have also the indexer code written in GO that is taking ~35GB of ram, previously it wasnt when I had like 10k indexed data. Here is the ES query in img.

Also when I make same request through Postman, it executes almost instantly.

[graceful linden]

it does not matter if the response is small. Because if you have to look through 5 trillion datasets, in order to get that small response, then your search will take long.

the reason can be anywhere