I have a table(mysql) containing around 20,000 records and I am trying to build a auto complete search box for my website. Someone told me that auto-complete search for such a large number of records would be very slow and hence is of no worth. I just want to consult some more people that is it a good idea to have a auto complete search for such data?
Performance : Auto Complete Search for a large amount of data?
mysql;search;database;site search
20,000 records is not a lot at all. It's not uncommon for a table to have millions of records and, if your database is designed properly, still be very fast. So using Autocomplete  with a table of 20,000 or even one million records is definitely feasible and shouldn't be slow. If it is you need to revisit your database design and SQL queries to make sure they are properly optimized.