Just a quick tip today that may seem obvious after you have been working with MOSS Enteprise Search for a while. Start small. If you are going to be debugging a new entity, don't configure the BDC to load all the records of the table, stick a TOP clause in your SQL statement or stored procedure to limit the crawl. Crawling is really slow, working with 50 rows is a lot faster than waiting for it to index 50,000 (or millions for that matter). Once you think you have the right results being returned, schedule a crawl for after work and if you are lucky it might be done in the morning when you get back the next day.
Also another quick tip. If during the debugging process, the profile page of the SSP is not displaying the right data, reset IIS. Those profile pages get cached. In my case it was displaying a value of 1 for this new column I added for every single item indexed.
Read the complete post at http://www.dotnettipoftheday.com/blog.aspx?id=380