Configurable custom additional span attributes for the sql clients

[vecerek]

What is the problem this feature would solve?

As far as I'm aware, it is not possible to configure a SQL client with default custom span attributes that would be added every time a sql query is executed. This is only possible for the generic @effect/sql client but not the specific implementations like @effect/sql-mysql2.

Making this possible would allow the user to adapt the span to achieve an "ideal" visualization in their observability vendor's systems. For example, there are a few extra attributes I would need to globally set for the sql client for the spans to show up as I'd like.

What is the feature you are proposing to solve the problem?

I would either like the sql client "implementation" take an optional configuration field called additionalSpanAttributes in its constructor, or add a mechanism similar to the statement transformer that would take the additional span attributes from the fiberRef and apply them to the span here.

What alternatives have you considered?

No response