Specify amounts of value you provided to previous organizations through your database administration work
You need to quantify the exact ways in which companies and organizations you previously worked for have saved on costs, as that is what's always a primary concern in business. It's not about bragging but rather, it's about detailing how much value you added to your previous employers. For example, see how the person writes "saved $250K annually in lower-tech support calls by migrating from NT servers to VMware." Other ideas of metrics you can highlight could be improvements in database or query processing speeds, new technologies you introduced, or other improvements to general operations.