Christoph Berg <myon@debian.org> writes:
> For 2), Tom said that configurability is 1) often much less useful
> than originally planned, and 2) tools have to cope with both settings
> anyway, making implementing them harder. Plus, switching at run-time
> makes the result even less predictable.
To clarify that last bit: if some clients run with the GUC on and some
with it off, you have a mess. Even statements that are completely
identical will have different query IDs under the two settings.
If this GUC sticks around, it should be at least PGC_SUSET (on
the analogy of compute_query_id) to make it harder to break
pg_stat_statements that way.
regards, tom lane