I recently came across a scenario where I wanted to reindex specific item(s)/folder instead of full content tree.
Typically I would have reindexed Sitecore_Master DB which takes good amount of time to rebuild all items.
Instead I chose the item(s)/folder, navigated to Developer tab and clicked Re-Index Tree. It was done less than a minute!
This will rebuild the Item(s) to all the indexes in your solution and I feel this is very quick as compared to traditional re-index.
Note: If you don’t see Developer tab in the menu, you need to enable it by right-clicking on the menu and select the developer option.
Hope this helps someone. Any questions, leave a comment.