Elasticsearch推向新类型

Question

Is it possible to get a projection as a query result in elasticsearch?

For example:

I have 3 types in my index:

User { Id, Name, Groups[], Location { Lat, Lon } }
Group { Id, Name, Topics[] }
Message { Id, UserId, GroupId, Content}

And I want to get the number of messages and users in a group in a given area, so my input would be:

{ Lat, Lon, Distance, GroupId }

and the output would be:

Group { Id, Name, Topics, NumberOfUsers, NumberOfMessages }

where the actual output of the query is a combination of data returned by the query and aggregations within that data.

Is this possible?

Answer 1

There are no JOINs in Elasticsearch (except for parent-child, but those shouldn't be used for heavy joining either). With your current data model you'll only be able to to application-side JOINs and depending on your actual data that might be a lot of roundtrips. I don't think this will work out too well.

PS: Generally, please provide some simple test documents with usable data. If I have to put together a test data set to try out your problem, your chances that anybody will actually try it will get rather slim.