How do I prioritize results that I pass in?

Question

I have the following bool query:

POST _search
{
  "query": {
    "bool" : {
      "must" : {
        "term" : { "title" : "technology" }
      },
      "should" : [
        { "term" : { "text" : "companies that produce hardware" } }
      ]
    }
  }
}

Suppose this returns the following document id's (in order):

1. netflix
2. google
3. microsoft
4. dell
5. intel

Before this query happens I query a separate database and get the following results (in order):

1. intel
2. amazon
3. dell

I'd like to prioritize the results of my database over those of elasticsearch so that I get the following results:

1. intel
2. dell
3. netflix
4. google
5. microsoft

(Notice that amazon doesn't show up since we're not trying to create an elasticsearch document out of thin air).

Answer 1

You can use script based sorting, which allows you to sort your data based on a custom script.

Use a script that assigns a priority value for each result. Could be something like:

{
  "query": {
    "bool" : {
      "must" : {
        "term" : { "title" : "technology" }
      },
      "should" : [
        { "term" : { "text" : "companies that produce hardware" } }
      ]
    }
  },
  "sort": {
    "_script": {
      "type": "number",
      "order": "asc",
      "script": {
        "lang": "painless",
        "source": "if (doc['company'].value.equals('intel')) return 0;
                   else if (doc['company'].value.equals('amazon')) return 1;                          
                   else if (doc['company'].value.equals('dell')) return 2;                          
                   else return 3;
      }
    }
  }
}

I used company field since sorting on the '_id' field is discouraged, even though it's possible. Check out this link.

For more infomation, check Sorting, Scripting and Painless.

Hope it helps!