Re: AW: Re: [GENERAL] Query caching

On Fri, 3 Nov 2000, Christof Petig wrote:

> Karel Zak wrote:
>
> > On Thu, 2 Nov 2000, Zeugswetter Andreas SB wrote:
> >
> > >
> > > > Well I can re-write and resubmit this patch. Add it as a
> > > > compile time option
> > > > is not bad idea. Second possibility is distribute it as patch
> > > > in the contrib
> > > > tree. And if it until not good tested not dirty with this main tree...
> > > >
> > > > Ok, I next week prepare it...
> > >
> > > One thing that worries me though is, that it extends the sql language,
> > > and there has been no discussion about the chosen syntax.
> > >
> > > Imho the standard embedded SQL syntax (prepare ...) could be a
> > > starting point.
> >
> > Yes, you are right... my PREPARE/EXECUTE is not too much ready to SQL92,
> > I some old letter I speculate about "SAVE/EXECUTE PLAN" instead
> > PREPARE/EXECUTE. But don't forget, it will *experimental* patch... we can
> > change it in future ..etc.
> >
> > Karel
>
> [Sorry, I didn't look into your patch, yet.]

Please, read my old query cache and PREPARE/EXECUTE description...

> What about parameters? Normally you can prepare a statement and execute it

We have in PG parameters, see SPI, but now it's used inside backend only
and not exist statement that allows to use this feature in be<->fe.

> using different parameters. AFAIK postgres' frontend-backend protocol is not
> designed to take parameters for statements (e.g. like result presents
> results). A very long road to go.
> By the way, I'm somewhat interested in getting this feature in. Perhaps it
> should be part of a protocol redesign (e.g. binary parameters/results).
> Handling endianness is one aspect, floats are harder (but float->ascii->float
> sometimes fails as well).

PREPARE <name> AS <query>
[ USING type, ... typeN ]
[ NOSHARE | SHARE | GLOBAL ]

EXECUTE <name>
[ INTO [ TEMPORARY | TEMP ] [ TABLE ] new_table ]
[ USING val, ... valN ]
[ NOSHARE | SHARE | GLOBAL ]

DEALLOCATE PREPARE
[ <name> [ NOSHARE | SHARE | GLOBAL ]]
[ ALL | ALL INTERNAL ]

An example:

PREPARE chris_query AS SELECT * FROM pg_class WHERE relname = $1 USING text;

EXECUTE chris_query USING 'pg_shadow';

Or mean you something other?
Karel