the application is on the cloud “GAE” , so i think it will not be an issue increasing memory usage few more KBs to hold that Data structure.
but i agree with you code will be more complex and background jobs will be harder to maintain.

maybe this will make us either take solution (1), and maybe make some sort of storing for that Data Structure in GAE data store. but still this is going to make its code highly complex.

again thanks Carlosdl

regards
mohammad

This is just a thought, as I have never developed for GAE and thus don’t know of any good practices specific to it, nor do I know the inner details of how the GAE’s data store works.

For a better response time I think your 2nd option (a memory tree structure) would be the best one, unless the GAE offered some kind of caching capability, which could make queries faster when data changes are not frequent, in which case your best option would probably be the first one (the statistics table).

Using a memory structure to store the data will probably be faster (depending on the type of structure and the search algorithms used), but would consume more memory and would add some complexity to the application code. Also, a background job would probably be needed to handle updates for expiring items.

I would probably tend to prefer this option, but I really think that both approaches should be tested enough, to make a final decision.

I am afraid it is not a database. it is Google App Engine Data store.

counting is done to find numbers between brackets in searching filter “narrow search”.
these numbers are real time data , changed by changing data itself.
kindly visit careerbuilder.com and check its narrow filter for more details.
or please tell me if i should explain further more about usage here.

i did not test it yet, but as a cloud computing platform it will cost more if it needs more CPU/… resources.
i want to get the optimum design or best practice here.

regards
mohammad

But, from the problem description I understand that you are in fact using a database, but you think that executing count queries every time, it will be too slow. Is my understanding correct ? If so, what database are you using ?

This is important, as depending on that different methods could be considered. For example, if Oracle, maybe a materialized view could be a good option (which would be the first option you mentioned), if MySql, maybe a memory table (heap) could be considered.

“…even though i still think this is not enough ”

Have you tested this approaches. Is there a reason to think this won’t be enough ?

hope anyone can help….
any questions or suggestions are welcomed !!!

regards
mohammad s.