If you're conducting a literature review for your dissertation, it's not considered complete until your defense. To maintain an up-to-date review of the literature, you'll want to be aware of any relevant new studies or literature published after you've completed your literature review. Instead of periodically repeating your literature search, you can set up search alerts so that any literature that matches your search criteria gets automatically sent to your inbox.
How to set up a search alert:
The first step in creating a search alert is to create a search that returns results similar to what you'd like to receive alerts for.
On the page that displays your results list, most databases provide a link to create an alert to the right of your results.
Example: Creating an alert in PsycINFO: