querying elasitcsearch parent child documents - parent-child

Question

We work with two types of documents on elastic search (ES): items and slots, where items are parents of slot documents.
We define the index with the following command:
curl -XPOST 'localhost:9200/items' -d #itemsdef.json
where itemsdef.json has the following definition
{
"mappings" : {
"item" : {
"properties" : {
"id" : {"type" : "long" },
"name" : {
"type" : "string",
"_analyzer" : "textIndexAnalyzer"
},
"location" : {"type" : "geo_point" },
}
}
},
"settings" : {
"analysis" : {
"analyzer" : {
"activityIndexAnalyzer" : {
"alias" : ["activityQueryAnalyzer"],
"type" : "custom",
"tokenizer" : "whitespace",
"filter" : ["trim", "lowercase", "asciifolding", "spanish_stop", "spanish_synonym"]
},
"textIndexAnalyzer" : {
"type" : "custom",
"tokenizer" : "whitespace",
"filter" : ["word_delimiter_impl", "trim", "lowercase", "asciifolding", "spanish_stop", "spanish_synonym"]
},
"textQueryAnalyzer" : {
"type" : "custom",
"tokenizer" : "whitespace",
"filter" : ["trim", "lowercase", "asciifolding", "spanish_stop"]
}
},
"filter" : {
"spanish_stop" : {
"type" : "stop",
"ignore_case" : true,
"enable_position_increments" : true,
"stopwords_path" : "analysis/spanish-stopwords.txt"
},
"spanish_synonym" : {
"type" : "synonym",
"synonyms_path" : "analysis/spanish-synonyms.txt"
},
"word_delimiter_impl" : {
"type" : "word_delimiter",
"generate_word_parts" : true,
"generate_number_parts" : true,
"catenate_words" : true,
"catenate_numbers" : true,
"split_on_case_change" : false
}
}
}
}
}
Then we add the child document definition using the following command:
curl -XPOST 'localhost:9200/items/slot/_mapping' -d #slotsdef.json
Where slotsdef.json has the following definition:
{
"slot" : {
"_parent" : {"type" : "item"},
"_routing" : {
"required" : true,
"path" : "parent_id"
},
"properties": {
"id" : { "type" : "long" },
"parent_id" : { "type" : "long" },
"activity" : {
"type" : "string",
"_analyzer" : "activityIndexAnalyzer"
},
"day" : { "type" : "integer" },
"start" : { "type" : "integer" },
"end" : { "type" : "integer" }
}
}
}
Finally we perform a bulk index with the following command:
curl -XPOST 'localhost:9200/items/_bulk' --data-binary #testbulk.json
Where testbulk.json holds the following data:
{"index":{"_type": "item", "_id":35}}
{"location":[40.4,-3.6],"id":35,"name":"A Name"}
{"index":{"_type":"slot","_id":126,"_parent":35}}
{"id":126,"start":1330,"day":1,"end":1730,"activity":"An Activity","parent_id":35}
I'm trying to make the following query: search for all items within a certain distance to a location that have children (slots) in the specified days and within certain start and end ranges.
An item with more slots fulfilling the condition should score higher.
I tried starting with existing samples but the docs are really scarce and its hard to move forward.
Clues?

Answer 1

I don't think there is a way to write an efficient query that would do something like this without moving location to slots. You can do something like this, but it can quite inefficient for some data:
{
"query": {
"top_children" : {
"type": "blog_tag",
"query" : {
"constant_score" : {
"query" : {
... your query for children goes here ...
}
}
},
"score" : "sum",
"factor" : 5,
"incremental_factor" : 2
}
},
"filter": {
"geo_distance" : {
"distance" : "200km",
"location" : {
"lat" : 40,
"lon" : -70
}
}
}
}
}
Basically, what this query is doing is this, it takes your range query or filter for children and whatever other conditions you need and wraps it into constant_score query to make sure that all children have score of 1.0. The top_children query collects all these children and accumulates their scores to the parents. And then filter filters out parents that are too far away.