Optimizing queries for the next and previous element

Question

I am looking for the best way to retrieve the next and previous records of a record without running a full query. I have a fully implemented solution in place, and would like to

Answer 1

Here is an idea. You could offload the expensive operations to an update when the grocer inserts/updates new offers rather than when the end user selects the data to view. This may seem like a non-dynamic way to handle the sort data, but it may increase speed. And, as we know, there is always a trade off between performance and other coding factors.

Create a table to hold next and previous for each offer and each sort option. (Alternatively, you could store this in the offer table if you will always have three sort options -- query speed is a good reason to denormalize your database)

So you would have these columns:

• Sort Type (Unsorted, Price, Class and Price Desc)
• Offer ID
• Prev ID
• Next ID

When the detail information for the offer detail page is queried from the database, the NextID and PrevID would be part of the results. So you would only need one query for each detail page.

Each time an offer is inserted, updated or deleted, you would need to run a process which validates the integrity/accuracy of the sorttype table.