Google automatically finds synonyms and variations on the keywords you search for. Other databases don't always have the same capabilities. Here are a few tips which can make your database searches more effective:
Boolean operators: AND, OR, NOT
Phrase searching: put quotes around your keywords to find the words together, in that order. Might limit your search too much; use carefully.
Truncation: in most databases, an asterisk at the end of a word will find all different endings.
Controlled vocabulary or subject headings: these are terms added to articles or books to help you find related topics. In some databases, you can click on these or add them to your search to help improve your results.