Searching by user name will INCREASE the speed. Why? Since the user ID is a separate field in the posts table. A search function that first looks up the userID for a user name (fast search, only 300.000 or so records in that table) and then looks up the posts in the posts table by UserID (fast search, looking up by a integer numeric is very efficient) is much, much more efficient than a full text search over all the post contents. Especially when the userID field in the posts table is indexed. Anything that reduces the need for full text searches and "WHERE < string expression > LIKE < pattern >" will speed up the site. There's only one downside. By indexing more fields, updates and additions to the table will slow down. On the other hand, I expect that the number of database searches far exceeds the number of additions/updates/deletions, easily by a factor of 10,000 or more. Not a real problem. I'd love to see the "search by user name" functionality reinstated. In fact, I'd love to see as many "search by" options as possible, preferably with AND and OR clauses. That would both speed up the searches AND give the user the most relevant results.

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