# Large data set: paginating, sorting - application? database

**URL:** <https://www.ruby-forum.com/t/large-data-set-paginating-sorting-application-database/111098>\
**Category:** Rails\
**Created:** [August 2, 2007, 4:55pm UTC](https://www.ruby-forum.com/t/large-data-set-paginating-sorting-application-database/111098 "2007-08-02T16:55:21Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![sasha](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/s/54ee81/32.png) [@sasha](https://www.ruby-forum.com/u/sasha)\
**Post date:** [August 2, 2007, 4:55pm UTC](https://www.ruby-forum.com/t/large-data-set-paginating-sorting-application-database/111098/1 "2007-08-02T16:55:21Z")

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- My ultimate goal is to paginate a large data set (to have something  
that looks like a data grid)

- I am using paginating\_find (but am open to other suggestions)

- Being able to resort the data set by column is a must have. The two  
options I have are: (1) retrieve the data set and sort it in the  
application (model or controller) - this is expensive and probably  
won’t scale for large data sets, and (2) do the sorting in the  
database

- My actual find/select query is somewhat hairy:

Classname.find(:all,  
:select =\> “some\_fields\_go\_here,  
if ( (some calculation) \> (another calculation),  
return\_certain\_field …”,  
:joins =\> [ “inner join on something … left join on  
something\_else … inner join on another\_thing” ],  
:conditions =\> [“some conditions”],  
:order =\> some\_order )

- Naturally, I am trying to avoid having many db calls (I mean, it’s a  
large data set - potentially tens of thousands of records)

What is the best/recommended way to handle this (this meaning a  
relatively complex query with joins, calculations, pagination, and  
sorting)? Should I be building stored procedures (I am using MySQL)?  
Is there a clever way to do this on the application side without  
incurring a huge cost when sorting? Any help would be appreciated.

Thanks so much,

–sasha