Feature request: spec support for using bound parameters as attribute values

[mitchsw]

Would it be feasible to support attribute values being specified via a query's parameter bindings?

Idea

I'd like to support prepared statements like the following (and stay within the sqlcommeter spec):

LOG:  execute my-demo-stmt: SELECT * FROM FOO WHERE ID = $1 /*application='app-1', traceparent=$2*/
DETAIL:  parameters: $1 = 1234, $2 = '00-5bd66ef5095369c7b0d1f8f4bd33716a-c532cb4098ac3dd2-01'

This would necessitate an extension to sqlcommeter spec. Something like:

FIELD      ::=  <SERIALIZED_KEY>=<VALUE>
VALUE      ::=  <SERIALIZED_VALUE> | <PARAM_NUM>
PARAM_NUM  ::=  $[0-9]+

Motivation

My objective is to enable the performance benefits of prepared statements, whilst still being able to use a unique per-query traceparent.

In Postgres, it is technically possible to prepare and execute a statement like the example above. (The $2 parameter is simply unused by the query planner, but still appears in the statement log.) I am exploring adding this support to DataDog/dd-trace-go's SqlCommeter.

Would this feature in the spec be generally useful?