We are crawling SQL server for employees details. Sync is done, data is crawled and indexed. I can see result set after searching employees name from Test Center, but when I click on result set, it opens a link like http://DOMAIN_NAME/db/HOSTNAME/DB_SOURCE_NAME/RANDOM_HASH_ID which is 404 not found.
But when I click on Cached, it shows result properly.
Being 6.10 I'm guessing you're using the built in database crawler, not the offboard connector.
If that's the case then the issue is most likely the server query that you have configured or the serve URL.
On the Crawl and Index > Databases page, make sure there is a valid entry in either Serve Query or Serve URL Field.