No results for top_children query; same has_child query works

Matthew_A_Brown · February 6, 2012, 10:10pm

Hi all,

I've got a situation where running a top_children query returns no
results; running the same query wrapped in a has_child returns the
expected result. I know that top_children may miss parent document
results in the case where there are lots of matching children per
parent; but since in this case top_children returns nothing at all, it
seems that that's not what's going on.

I can try to put together a reduction, but first just wanted to make
sure my understanding of top_children/has_child is correct, and that
what I'm describing is not expected behavior.

Thanks!
Mat

kimchy · February 7, 2012, 10:13am

It sounds strange, it should return a value… . A recreation would help, thanks!

On Tuesday, February 7, 2012 at 12:10 AM, Matthew A. Brown wrote:

Hi all,

I've got a situation where running a top_children query returns no
results; running the same query wrapped in a has_child returns the
expected result. I know that top_children may miss parent document
results in the case where there are lots of matching children per
parent; but since in this case top_children returns nothing at all, it
seems that that's not what's going on.

I can try to put together a reduction, but first just wanted to make
sure my understanding of top_children/has_child is correct, and that
what I'm describing is not expected behavior.

Thanks!
Mat

Matthew_A_Brown · February 16, 2012, 4:25pm

Finally put together a reduction for it -- the kicker seems to be
having a nested field in the parent type with the same name as the
field you're searching in the child type. I've opened a ticket:

github.com/elastic/elasticsearch

top_children query returns no results when child field has the same name as a nested field as a nested field in the parent mapping

opened 04:22PM - 16 Feb 12 UTC

closed 01:13PM - 19 Feb 12 UTC

outoftime

>bug v0.19.0.RC3

What reproduces the problem is when you have a field, say, "body", in the child …type, and you're searching on that field in `top_children`. If the parent type also has a nested field with the name "body", then the `top_children` query will return no results; the same `has_child` query/filter does return results. Here's a reduction (or [download](https://gist.github.com/1846196)): ``` curl -XDELETE localhost:9200/test?pretty=true echo "" curl -XPUT localhost:9200/test?pretty=true echo "" curl -XPUT localhost:9200/test/parent/_mapping?pretty=true -d '{"parent":{"properties":{"name":{"type":"string","index":"analyzed"},"notes":{"properties":{"body":{"type":"string"}}}}}}' echo "" curl -XPUT localhost:9200/test/child/_mapping?pretty=true -d '{"child":{"_parent":{"type":"parent"}, "properties":{"body":{"type":"string","index":"analyzed"}}}}' echo "" curl -XPUT localhost:9200/test/parent/1?pretty=true -d "{\"name\":\"parent document\"}" echo "" curl -XPOST 'localhost:9200/test/child/_create?parent=1&pretty=true&refresh=true' -d '{"body":"pizza monster"}' echo "" curl -XGET localhost:9200/test/parent/_search?pretty=true -d '{"query":{"top_children":{"type":"child","query":{"query_string":{"query":"pizza monster","fields":["body"]}}}}}' echo "" curl -XGET localhost:9200/test/parent/_search?pretty=true -d '{"query":{"has_child":{"type":"child","query":{"query_string":{"query":"pizza monster","fields":["body"]}}}}}' echo "" ```

Thanks!
Mat

On Feb 7, 5:13 am, Shay Banon kim...@gmail.com wrote:

It sounds strange, it should return a value… . A recreation would help, thanks!

On Tuesday, February 7, 2012 at 12:10 AM, Matthew A. Brown wrote:

Hi all,

I've got a situation where running a top_children query returns no
results; running the same query wrapped in a has_child returns the
expected result. I know that top_children may miss parent document
results in the case where there are lots of matching children per
parent; but since in this case top_children returns nothing at all, it
seems that that's not what's going on.

I can try to put together a reduction, but first just wanted to make
sure my understanding of top_children/has_child is correct, and that
what I'm describing is not expected behavior.

Thanks!
Mat