Oracle Database Discussions

I have a database that really seems to be slowing down as more and more information is added. I'm looking to find a way to speed things up a bit. I've heard two suggestions.

The first is to rename my tables and then recreate them and insert the data from teh original in primary key order. This seems like a lot of work but it makes sense that it could work. I'd like to hear from anyone that may have tried this to see if it really helped.

The second suggestion was to run ANALYZE TABLE on all of the tables in my database. I've been trying to read up on this command and I don't see what it is actually doing that would speed up performance. Could anyone help clarify or offer up other suggestions? I also don't know which options (estimate or calculate) I should use.

Thanks in advance,
Chris S.