Performance of will_paginate + stored programs

Question

Hi all,
What your experience with performance of will_paginate with stored procedures/functions? I have a few pipelined functions following the procedure described at http://wiki.rubyonrails.org/rails/pages/OracleStoredProceduresAsDataSource and uses will_paginate for it.
As you know, a code such as
paginate_by_sql([
"select col1, col2, col3 from table(function(?,?))", "#{param1}", "#{param2}",
], options)
will automatically form:
select count(*) from (select col1, col2, col3 from table(function(param1,param2)))
to count the results. This looks like it will result in Oracle needlessly retrieving data for col1, col2, etc when all that is needed is the number of results. Or is there (hopefully) some sophistication/intelligence that determines otherwise?
And then to get for example results 76-90 will_paginate forms:
select * from
(select raw_sql_.*, rownum raw_rnum_ from
(select col1, col2, col3 from table(function(param1,param2))) raw_sql_
where rownum <= 90) where raw_rnum_ > 75
Again, does this mean the pipelined function will still read all the data for results 1-75 first to form the "table"? If so, that would be a waste. Does it look like it's not ideal to use will_paginate with stored programs? Would appreciate to know what you think.
Thank you very much.
Johann
Edited by: johanntagle on Dec 9, 2008 4:06 AM

Answer 1

Short answer: it depends.
There will probobaly be very little difference in performance difference for a sipmle insert / update etc.
Multiple inserts / updates etc you will probobaly find faster with a stored procedure rather than n prepared statments as you only have to contact the database once vs n times.
Hope this helps!