Re: Nested Sets vs. Nested Intervals

Thank you very much, Vadim Tropashko.

Nested Intervals are very efficient for updating and selecting hierarchical categories. I am creating a web application/directory from it, but it would be more convenient for the user to retrieve its children from an array of folder names in the URL (seperated by dots or slashes, like google groups does for its usenet categories) instead of a category_id.

Both dmoz and yahoo also retrieves its immediate subcategories by the array of folder-names in the URL; Unlike some other directories that retrives its immediate subcategories from a category_id in the URL. Is there any efficient way to retrieve its immediate subcategories by an array of folder-names such as dmoz and yahoo?

Basically, it's like replicating a file system: an array of folder names can point to the category_id to retrieve their children. However, it would take recursive SELECTs to find the category_id from the array of folder names. I could store the whole path in each row, but it would be very inefficient to update a category. Is there an efficient way to do this?

Thank you very much! Received on Wed Nov 09 2005 - 22:01:46 CET