Disadvantages

Search engines work by creating indexes of published HTML web pages that were, initially, "static". With the advent of dynamic web pages, often created from a private database, the content is less visible^[2]. Unless this content is duplicated in some way (for example, as a series of extra static pages on the same site), a search may not find the information it is looking for. It is unreasonable to expect generalizedweb search engines to be able to access complex database structures, some of which in any case may be secure.