Is MEDLINE enough?

Recently, several people have asked me about which databases are important to search. I usually ask what the purpose of their search is - couple of 'good' recent articles, a more comprehensive search or a 'no stone unturned' exhaustive search?

If you are looking for a couple of good articles then MEDLINE is probably enough. A more comprehensive search should take you beyond MEDLINE to EMBASE, SCOPUS, Science Citation Index, Google Scholar and depending on your topic, an appropriate specialty database, such as CINAHL or PsycINFO. An exhaustive search will include all of the above plus multiple specialty databases, citation analysis, grey literature, web searching and hand searching the top journals in the discipline.

If you're having trouble deciding which databases you should search for your question or project, consult with your librarian.