Send query heartbeat while downloading results

[wendigo]

Describe the feature

trinodb/trino#25267

Describe alternatives you've considered

No response

Are you willing to submit PR?

• Yes I am willing to submit a PR!

[hashhar]

@wendigo Does this result in queries failing midway? Should it be considered as a bug?

[wendigo]

@hashhar if the client is slow then yeah, it can fail in between

[jayceslesar]

would be awesome to get some momentum here, I took a look at the java impl of this (I am not fluent in java) and have a very rough idea of how I can implement but a little unsure what endpoint I need to actually send requests to while the downloading is happening.

I am hoping to implement streaming a result set back from trino into a file that is downloaded by users through some [W|A]SGI framework in python for some context.

Alternatively, this could be implemented by clients today by paginating using OFFSET in queries to consume query results in chunks but this could result in inconsistent responses if data the user is querying changes in between requests.