Use Sort object in "delete by query"

[ramikg]

The delete by query API's sort property supports the Sort object:

"sort": {
  "timestamp": {
    "order": "desc",
    "unmapped_type": "date"
  }
}

But the property's type does not reflect this fact.

This PR changes the type of sort from string[] to the more general Sort object (as used by the search API):

But the body is missing the sort parameter, this PR adds it as Sort object.

[l-trotta]

Hello @ramikg, thank you for you interest in contributing to the spec!
That sort field in DeleteByQueryRequest is a query param and cannot be an object, if you check SearchRequest you can see that it has the same field.
One thing we have to do for sure is making them the same, so sort in DeleteByQueryRequest should also be a string | string[]. But I'm not finding any evidence that DeleteByQueryRequest has a body field sort, did you manage to reproduce it?

[ramikg]

Oops, I've missed that the sort property I've modified is under query_parameters.
I've restored the query parameter to its original form.

I tried using the sort property (exactly as provided above) in the body and verified that Elasticsearch actually parses it (e.g. wrong order or unmapped_type values resulted in an error).
I've checked this in Elasticsearch versions 9.1.2 & 8.19.2.

[l-trotta]

@ramikg thanks for checking! I've done a bit of digging and this seems to be part of a larger issue, where delete by query actually supports all parameters supported by search request. let's merge this for now, then we'll see what to do about the rest :D

[ramikg]

Thank you!

By the way, this seems to be the case for "update by query" as well (and perhaps for additional APIs).

[l-trotta]

We've investigated this a bit more and found out that the sort body parameter actually does nothing in this context, and moreover the sort query parameter isn't actually supported. I'm reverting this and deprecating the existing query param, sorry for the confusion!

[ramikg]

We've investigated this a bit more and found out that the sort body parameter actually does nothing in this context, and moreover the sort query parameter isn't actually supported. I'm reverting this and deprecating the existing query param, sorry for the confusion!

Could you please elaborate?

I may be missing something, but in my tests it seems that the sort body parameter is effective. For example:

POST test/_bulk
{ "index": {} }
{ "amount": 1 }
{ "index": {} }
{ "amount": 2 }
{ "index": {} }
{ "amount": 3 }
{ "index": {} }
{ "amount": 4 }
{ "index": {} }
{ "amount": 5 }

POST test/_delete_by_query
{
  "query": {
    "match_all": {}
  },
  "sort": {
    "amount": {
      "order": "asc",
      "unmapped_type": "long"
    }
  },
  "max_docs": 2
}

After running the commands above, the remaining amounts were {3, 4, 5}, and then when I deleted again with "order": "desc" then I was left with just 3.
(I've also tried several other experiments.)

[l-trotta]

@ramikg ah that's how! sorry I was testing with size, not considering max_docs. reverting again ^^"