GUC_REPORT for protocol tunables was: Re: Optimize binary serialization format of arrays with fixed size elements

On Sun, Jan 22, 2012 at 11:47 PM, Mikko Tiihonen
<mikko(dot)tiihonen(at)nitorcreations(dot)com> wrote:
> * introduced a new GUC variable array_output copying the current
>  bytea_output type, with values "full" (old value) and
>  "smallfixed" (new default)
> * added documentation for the new GUC variable

If this variable changes protocol-level layout
and is user-settable, shouldn't it be GUC_REPORT?

Now that I think about it, same applies to bytea_output?

You could say the problem does not appear if the
clients always accepts server default. But how can
the client know the default? If the client is required
to do "SHOW" before it can talk to server then that
seems to hint those vars should be GUC_REPORT.

Same story when clients are always expected to set
the vars to their preferred values. Then you get
clients with different settings on one server.
This breaks transaction-pooling setups (pgbouncer).
Again, such protocol-changing tunables should be
GUC_REPORT.

--
marko