Module search_box and "Advanced Search"
The search has been improved in Tikiwiki 3.0.
If you are using mysql as the database behind your tikiwiki installation, you can user the Module search_box, which allows advanced searches, like BOOLEAN searches and many other improvements of the search feature, using a simple syntax:

Example: you can search for "Dynamic items list" in the search box, without double quotes, and you'll find hundreds of objects containing some or all of the words.

If you click on the advanced search checkbox, and surround your words by double quotes, you'll geet a very narrow result, with the page containing the three words on its name in that list:

See Search Admin and Search Details for more info on this module and the search modes.