Re: pgbench doc fix

Hello Tatsuo-san,

> pgbench doc (and some comments in pgbench.c) regarding "-M prepared" 
> option is not quite correct. [...] Actually "extended" mode uses 
> prepared statements too.

Ok, I understand that you mean that PQsendQueryParams uses an unamed query 
internally to separate parsing & execution, which seems indeed to be the 
case by looking at the libpq client-side code.

However, if I'm not mistaken, the params version always sends and possibly 
reparses the query each time (is there a server side cache to avoid 
re-parsing? a quick scan in the sources did not return a clear answer to 
this question, but I think to recall that the answer is yes).

> Patch attached.

Patch applies cleanly, compiles, doc generation ok, global & local tests 
are ok.

I'm fine having a more precise wording.

Maybe I would have also insisted on the fact that there is an explicit vs 
an implicit PREPARE, if it relies on a server-side cache. The "extended"
documentation entry does not say that it is prepared.

I created an entry in the CF and marked the patch as ready anyway.

-- 
Fabien.