Re: Myth of the database independent applications (Was: Are you using PL/SQL)

On 25 mai, 22:47, zigzag..._at_yahoo.com wrote:
>
> > > > > I have worked so many projects using [the three-tier]
> > > > >architecture and performance has never been an issue.
>
> > > > If you don't mind, and for better mutual understanding, would
> > > > it be possible to have a (very rough) idea of some metrics
> > > > for one of these systems ?
>
> > > > I'm notably thinking of system purpose and :
>
> > > > - size of stored data (in your prefered unit)
> > > > - size of daily data growth
> > > > - number of simultaneous users (peak would be most welcome)
> > > > - average and guaranteed response time for user interface operations
> > > > - number of transactions over your prefered time period.
> > > > (peak would be most welcome)
>
> > > Our database were up to 100GB large. 95% of our queries were indexed
> > > based. Systems are used by up to 100 concurrent users
>
> > I forgot to ask which kind of hardware you use for
> > such a system, sorry
>
> HP UNIX boxes database server. Windows boxxes - application server.
> Usre interface are web based.

A few more questions, Zigzag, hopefully the last ones :-)

• On a given site, there is one database server box and one (more ?) application server box, right ? How much memory and CPUs do they have (for the figures given above) ?
• Presumably, the unix box runs Oracle. Do you support another database ?
• In the business layer, are (some) selects written "by hand", or do you always use an object/relational mapper like Hibernate ?
• Which platform/framework/language do you use ?
• What was the main rationale behind selecting three-tier ? Is it because it is the standard architecture for web UIs, or are there other reasons ?

Thanks much

• Raoul