Content Indexing also known as CI is a great feature to speed up item searching through mailboxes. I had to rebuild a CI database for a mailbox yesterday because there were some errors showing up on application log (I dont really remember the errors now) which were indicating that the CI was unable to update few items from database. Turned out the problem was not with database but with a faulty CI catalog associated with that database. After a good 2 hours of troubleshooting we figured out that the problem was with the faulty CI database associated with that database. Here is the process to manually delete the CI catalog and rebuild it and of course this is how we did it. Its not very difficult though you need to take care that you are deleting the correct CI database.
First of all locate the database locations on the physical drive.
Your indexing catalogs are located within this folder.
Now if you multiple databases homed within the single folder you may find more than one Catalogs created.
In such case I use the built in script GetSearchIndexForDatabase.ps1 to find out which catalog belongs to which database. The script uses the path of index catalogs to help you determining the name of its associated database. See figure below.
Once you are done with determination of associated database you can simply stop the Microsoft Exchange Search service and then remove the appropriate catalog based on the output of the script and then start the Microsoft Exchange Search service again.
After deleting the catalog files the service may take some time to enter the started status.
Well, I updated this post because someone pointed out an irrelevant infomration here. I would like to thank Jack who spent his time and corrected me on this. Thanks much, Jack 🙂