Index comment/note as part of commentable

Currently on elasticsearch, comments/notes are searched as individual entities.

It may be nice if comments/notes are indexed as part of the commentable (e.g. issues or merge requests). This way if a phrase was in the comment of an issue, searching that phrase would mean the issue would appear in search result. The reason for this is that often additional information are added as comments.

Problem to solve

Scenario: If we have an issue with "elasticsearch" as keyword, and later during the discussion, someone puts "epic" as a comment, searching "elasticsearch epic" would show neither the issue nor the comment.

Intended users

Ordinary user

Further details

When we try to search something, we often can recall a few keywords. However Those keywords may be spread across the issue description and comments, and the search would not show it.

Proposal

Index comments as part of the parent commentable (e.g. issues or merge requests).

This way, if a phrase was in the comment of an issue, searching that phrase would mean the issue would appear in search result. The reason for this is that often additional information are added as comments.

What does success look like, and how can we measure that?

Searching "elasticsearch epic" would show us the issue in search results, in the example above.

What is the type of buyer?

N/A

Links / references

Originated from https://gitlab.com/gitlab-org/gitlab-ee/merge_requests/14818#note_197379844