On Monday 27 January 2003 16:01, Torsten Curdt wrote: > Niclas Hedhman wrote: > > On Monday 27 January 2003 07:06, Torsten Curdt wrote: > >>>What do the database to try to find the 6th row? > >>> > >>>I think the answer is: scan the rest of the database after finding the > >>>ONLY 5 rows that already exist. > >> > >>No :) ...be sure - it doesn't > > > > Well, that depends on the WHERE clause. For instance; > > > > WHERE SQRT( SQ( a - b ) + SQ( c - d ) + SQ( e - f ) ) < g ; > > > > definately go through every record, whether the fields are indexed or > > not. > > Aaah - now I got you guys! (sorry for being that slow ;) > > Antonio, how comes that you always know you have 5 rows? This sounds > quite unusual to me...
I can answer part of that; 1. You have the "count" from somewhere else. 2. You know that objects of type X has N attributes, always fixed. 3. I have 10,000,000 random records of N types. I want the first one of each type. Sure there are other cases. Niclas --------------------------------------------------------------------- To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, email: [EMAIL PROTECTED]
