explain plan for slow database queries

[vvydier]

Going through various Otel repo's. I do not see if there is a way to issue an explain plan to add extended information about a slow database query (I am currently looking to add this functionality for MySQL where all you need to do is to re-send the SQL query with EXPLAIN pre-pended).
For a slow database span, this additional info will be an additional attribute/event with the EXPLAIN output in the span. This is something that should be off by default (for performance reasons, but can turned on if there is a need to investigate why a database is returning data slowly)
What is the best way to achieve this in Otel and is there an example in any language agent/prototype or is there a spec discussion that I can look at/engage in? Thanks