Is it possible to access to a different document by ID in script?

[yyz1989 (Yang)]

Dear friends,

Assume I have three documents in three indexes referencing each other through some attributes:

{
  "_index": "a",
  "_id": "a:0",
  "_source": {
    "child": "b:0"
  }
}

{
  "_index": "b",
  "_id": "b:0",
  "_source": {
    "child": "c:0",
    "parent": "a:0"
  }
}

{
  "_index": "c",
  "_id": "c:0",
  "_source": {
    "parent": "b:0"
  }
}

I wanted to perform a query to get all documents from index c whose "grand parent" is document "a:0". Unfortunately I cannot find out the way to do it in one query, so I have to query for documents whose parent is "a:0" from index b, and then query for documents from index c with the previous result as a filter.

To improve performance, it seems I have to insert "grand parent" document IDs to the documents in index c as well, then I just need to query once. In fact my index is quite large already, so I would prefer to insert this new field into the documents instead of reindexing everything. To do this I need to access to both indexes b and c, so that for each document in c I get parent document ID, and access to this document through ID index b to get "grand parent" document ID. However I also didn't find any example from the Web moving towards this direction.

I am not sure if I have explained my problem clearly. Is such solution really possible?

Any help is highly appreciated.

Best regards,
Yang

[spinscale (Alexander Reelsen)]

scripts cannot do further look ups to other documents. You would need to solve this issue at index time.

A look at the join datatype might help, but please take your time to properly read the documentation about it, as it comes with some limitations.

--Alex