SelectQuery with setPageSize

[Aradiusz Milewski <ar...@gmail.com>]

Hi

I have a SelectQuery with setPageSize. After running this query i would 
like to know on which index is specific object in this list, without 
fetching full list of objects into memory. Is it possible to do it using 
Cayenne API ?

Thanks
Arek

Re: SelectQuery with setPageSize

[Andrus Adamchik <an...@objectstyle.org>]

Hi,

List.indexOf(..) is a linear search (unless the list is known to be ordered and you can use binary search). So on average such lookup would resolve ~50% of the objects. 

Another way is to query for this object directly against the DB. Yet another is to do an in-memory check of the object against the original SelectQuery qualifier: 

   query.getQualifier().match(object);

Neither of the 2 will always be equivalent to List.indexOf(..). After all DB data changes over time, and also SQL and in-memory eval have subtle differences. So make a decision based on the task at hand.

Andrus 


> On Dec 1, 2014, at 1:05 PM, Aradiusz Milewski <ar...@gmail.com> wrote:
> 
> Hi
> 
> I have a SelectQuery with setPageSize. After running this query i would like to know on which index is specific object in this list, without fetching full list of objects into memory. Is it possible to do it using Cayenne API ?
> 
> Thanks
> Arek
>