It could read all the SET variables in at startup?
Peter Eisentraut wrote:
> Some time ago, the tab completion code for the SET command was changed to read
> the list of available settings from the pg_settings table. This means that
> by the time you're done completing SET TRANSACTION ISOLATION, you've already
> sent a query and the command will be disallowed. It's not a major issue, but
> I figured I'd mention it since it confused me a while ago. If someone has an
> ingenious plan for working around this, let me know.
>