Maintaining cities & countries database

[eluser]Randy Casburn[/eluser]
Hi Charlie,

There are a lot of dependencies that will determine the answer to the efficiency question. Which engine you're using, which indexing method you've chosen, whether you've chosen BINARY data types, the length of your keys, etc. etc. So for this answer...it depends.

The answer to the 'automagic' updates is yes this is done through "foreign" key constraints and cascading updates. MySQL tables can be created so that when a foreign key is established as a link to a primary key in a different table, any changes in the form of deletes, updates, etc. can be Cascaded or ignored by the child tables. This automates the process of keeping your indexing tables up to date for you.

Hope you find this helpful.

Randy