For those engines, you do not need to alert them as to updated or outdated pages. To be certain or to expedite the update of your page or site, you may wish to re-submit your site to make sure that the robot indexes it on the next crawl. There is a fine line between abuse and just enough for your requests. The term spamming also applies to website submission processes. Each engine has different guidelines.
Some companies own more than one search engine but use only one database.
Some companies own and use multiple databases based on certain parameters. Some search engines read other companies databases. That is especially true with metasearch engines. Depending on the timing of the submission, the database owner and the schedule and activity of the robot, it can take anywhere from seconds to several weeks to get listed in an index. Rankings are based on actual search activity of millions of Internet users.