Improve search performance-Configuration Issue

[snigdharao (SNIGDHA rao MADHAVARAM)]

I have indexed 85M documents and it doesnt respond fast .I have optimized my querys
I am assuming i need to change my configuration, Could you please let me know what needs to be changed

[Christian_Dahlqvist]

What does "not respond fast" mean in practice? What type of data and queries do you have? Are you always querying the full data set? What is the specification of the host Elasticsearch resides on?

[snigdharao (SNIGDHA rao MADHAVARAM)]

my autocomplete doesnot work fast.It works fine if the documents are 50M, but as the data grows its not fast

[Christian_Dahlqvist]

You will need to provide more details if someone is going to be able to help you. Answering the questions I asked would be a good start.

[snigdharao (SNIGDHA rao MADHAVARAM)]

So i have a query similar to this and the response is not fast ..It gets slow when more than 50 M documents are indexed
GET indexname/_search
{
"query":{
"constant_score": {
"filter": {
"bool":{
"should":[
{
"term":{
"agency_name":"police department"
}
}]
}
}

}
},
"aggs":{
"names":{
"terms":{
"field": "agency_name.keyword"
}
}
}
}

[snigdharao (SNIGDHA rao MADHAVARAM)]

i see performance issue while using query_string for my free text search usecase.
should i be using multifield for that scenario?