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From "Michal Malecki" <misie...@poczta.onet.pl>
Subject Re: What is N+1
Date Wed, 09 Feb 2005 12:04:17 GMT
Well, I think you need only simple join in your sql, no extra features of
ibatis needed:
select * from CHILD, PARENT where parent_id=PARENT.id;
am I right?
Michal Malecki

> What about relationships from the child up to the parent?  Are they also
> classified as N+1?
>
> Suppose we have child table with a fk of parent_id.
>
> if I do:
>
>   SELECT * from CHILD
>
> I'll get a column with parent_id with values.
>
> Now suppose I also want details pertaining to the parent_id along with
> the recordset of Child, I need not
> do 10 separate selects for the parent ...  is this also an N+1 problem?
>
> What is the preferred iBatis model for this?
>
> Cheers
>
> Abdullah
>
>
> Kris Jenkins wrote:
>
> > friendVU admin wrote:
> >
> >> What is n+1?
> >> .V
> >
> >
> >
> > n++!   :-P
> >
> > It's when each child object in a complex query has to be selected
> > seperately.  If 'parent' has 10 'children', you end up with 10+1
> > select statements being issued.  See the developer's guide under
> > 'Avoiding N+1 selects' for the full lowdown.  Version 2.0.9 comes with
> > new groupBy goodness to banish the N+1 problem.
> >
> > Kris
> >
>



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