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From "Jakob Bräuchi" <jbraeu...@gmx.ch>
Subject Re: Query startAt endAt
Date Tue, 18 Nov 2003 15:09:01 GMT
hi all,

i have to inform you, that paging by SQL is not yet an option :( because we
execute a select for each extent. but i think i found a way to improve
OJB-paging be it for collections or iterators.

as soon as time permits i will start working on the new solution. 


jakob

> Hi Jakob
> 
> <snip>
> >>
> >> Personally, I prefer LIMIT and OFFSET approach. Try to explain:
> > 
> > 
> > i also prefer the OFFSET and LIMIT.
> 
> +1
> 
> cu,
> Thomas
> 
> > we do have a problem with dbms only 
> > supporting OFFSET (oracle, sapdb etc.) there is a way to solve this 
> > problem by using an enclosing query:
> > 
> > select * from
> > (
> >   select ... , rownum as ojb_rnum where .... order by ...
> > ) where ojb_rnum between OFFSET and OFFSET + LIMIT
> > 
> > 
> > jakob
> > 
> > 
> >>
> >> StartAt = OFFSET
> >> endAt = OFFSET + LIMIT
> >>
> >> But:
> >>
> >> "endAt" indicates that it need to end at a given index. But this index
> >> does not necesary exists. Suppose 5 row in a table and we use:
> >>
> >> startAt = 1, endAt = 10
> >>
> >> The "endAt" index never will be reached. For me the endAt in this case
> >> does not exactly describe what we are requesting.
> >>
> >> On the other hand:
> >>
> >> startAt = 1, limit = 10 => This is correct, it means we will start at 1
> >> and we will retrieve at max 10 rows. But there is not an implicit 
> >> index of
> >> the  last one. Also using limit= 10 avoid us to doing some innecesary
> >> "maths". We cleary express the max. amount of rows we expect to 
> >> recieve in
> >> a very easy way. It is easier from a programming view. You will not
> need
> >> to sum the 2 values to get the endAt value.
> >>
> >> I just tried to explain my view point. Of course, comments are 
> >> welcome. :-D
> >>
> >> Best Regards,
> >>
> >> Antonio Gallardo
> >>
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> >>
> >>
> > 
> > 
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> > 
> 
> 
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