Different numHits 0.90.1 vs 0.90.2 filter with lookup terms

[scoolen]

Hi,

When I run an identical query on 0.90.1 and 0.90.2 I get different results:

{
  "filter": {
    "terms": {
      "field": {
        "id": "bar",
        "type": "doctype",
        "path": "lookupField"
      }
    }
  },
  "query": {
    "match_all": {}
  }
}

In 0.90.1 when filter returned no results the result of the query was also empty, i.e. 0 hits.
In 0.90.2 it returns everything. The latter behavior is probably better and more expected, but I haven't seen it documented anywhere. Did I miss something?

[scoolen]

There is a little bit more going on...

0.90.2 returns a MatchNoDocsQuery when it is the only filter applied, but returns all results when combined with a filter that returns everything (e.g. via an and filter).

[martijnvg]

@scoolen Do you have a particular test case for this change in behaviour? I'm curious if the document specified in the terms filter exists or if the path field exists.

I think the 0.90.1 behaviour is expected behaviour in most cases.

[scoolen]

Yes, I tested a couple of scenarios while switching back and forth between version 0.90.1 and 0.90.2:

1. Test with single lookup terms filter
2. Test with compound filter (type filter AND lookup)
3. Test with compound filter with just a single sub filter (lookup terms)

I tested these three scenarios with known values:

1. Empty lookup (no results)
2. No matching document lookup
3. Lookup with expected number of results

[martijnvg]

@scoolen I can confirm the difference in behaviour in both versions. It isn't reproducible in the current 0.90 and master branch. The following unreleased commit fixes this issue: 74a7c46

In case a filter is resolved to null which for example happens when a terms filter lookup can't find a document (but potentially also other filters return null) and in the case when there is no query, this just returns all docs. This issue has been has been fixed with the above commit.

In 0.90.1 the terms filter didn't return null and that is why this behaviour didn't occur in that version.

[Dynom]

Excellent news!

[Dynom]

For reference: this seems like a duplicate of #3356

[scoolen]

@martijnvg Ok cool. For now we will stick to 0.90.1 then. Thanks for your help.

[martijnvg]

@Dynom This is a duplicate of #3356, it isn't specific to just terms filter. I will close this issue now.