Thread: Re: [PATCHES] [SQL] 16 parameter limit
On the note of NAMEDATALEN, a view in the INFORMATION_SCHEMA definition is exactly 2 characters over the current limit. ADMINISTRABLE_ROLE_AUTHORIZATIONS Not that it's a great reason, but it isn't a bad one for increasing the limit ;) -- Rod Taylor > Are we staying at 16 as the default? I personally think we can > increase it to 32 with little penalty, and that we should increase > NAMEDATALEN to 64.
En Mon, 15 Apr 2002 23:19:45 -0400 "Rod Taylor" <rbt@zort.ca> escribió: > On the note of NAMEDATALEN, a view in the INFORMATION_SCHEMA > definition is exactly 2 characters over the current limit. > > ADMINISTRABLE_ROLE_AUTHORIZATIONS > > Not that it's a great reason, but it isn't a bad one for increasing > the limit ;) http://archives.postgresql.org/pgsql-general/2002-01/msg00939.php (Tom Lane says both SQL92 and SQL99 specify 128 as the maximun identifier length) Anyway, how does one measure the perfomance impact of such a change? By merely changing the constant definition, or also by actually using long identifiers? I can do that if it's of any help, for various values perhaps. -- Alvaro Herrera (<alvherre[a]atentus.com>) "Las cosas son buenas o malas segun las hace nuestra opinion" (Lisias)
On Mon, 15 Apr 2002 23:34:04 -0400 "Alvaro Herrera" <alvherre@atentus.com> wrote: > En Mon, 15 Apr 2002 23:19:45 -0400 > "Rod Taylor" <rbt@zort.ca> escribió: > > > On the note of NAMEDATALEN, a view in the INFORMATION_SCHEMA > > definition is exactly 2 characters over the current limit. > > > > ADMINISTRABLE_ROLE_AUTHORIZATIONS > > > > Not that it's a great reason, but it isn't a bad one for increasing > > the limit ;) > > http://archives.postgresql.org/pgsql-general/2002-01/msg00939.php > > (Tom Lane says both SQL92 and SQL99 specify 128 as the maximun > identifier length) > > Anyway, how does one measure the perfomance impact of such a change? > By merely changing the constant definition, or also by actually using > long identifiers? Name values are stored NULL-padded up to NAMEDATALEN bytes, so there is no need to actually use long identifiers, just change the value of NAMEDATALEN, recompile and run some benchmarks (perhaps OSDB? http://osdb.sf.net). If you do decide to run some benchmarks (and some more data would be good), please use the current CVS code. I sent in a patch a little while ago that should somewhat reduce the penalty for increasing NAMEDATALEN. Cheers, Neil -- Neil Conway <neilconway@rogers.com> PGP Key ID: DB3C29FC
Alvaro Herrera wrote: > (Tom Lane says both SQL92 and SQL99 specify 128 as the maximun > identifier length) > > Anyway, how does one measure the perfomance impact of such a change? > By merely changing the constant definition, or also by actually using > long identifiers? I can do that if it's of any help, for various values > perhaps. I think I would measure disk size change in a newly created database, and run regression for various values. That uses a lot of identifier lookups. -- Bruce Momjian | http://candle.pha.pa.us pgman@candle.pha.pa.us | (610) 853-3000+ If your life is a hard drive, | 830 Blythe Avenue + Christ can be your backup. | Drexel Hill, Pennsylvania19026
> > Anyway, how does one measure the perfomance impact of such a change? > > By merely changing the constant definition, or also by actually using > > long identifiers? I can do that if it's of any help, for various values > > perhaps. > > I think I would measure disk size change in a newly created database, > and run regression for various values. That uses a lot of identifier > lookups. With schemas, maybe there'd be less name lookups and comparisons anyway, since there's more reliance on oids instead of names? Chris