According to July 2007 Magento had/s plans for the search, see this blog post. Not sure if any of these plans have been actioned yet.
I also see “Enterprise Search” on the roadmap...whatever that is!! Perhaps you like this idea on improving the roadmap.
Overall, I would say that search functionality is good, but I agree it could be improved.
I would recommend though following Google’s format, which I believe is the same as Magento i.e. uses “AND” as the default, see: Google help section for more information.
However that is not to say the advanced search should not include an “OR” option. Perhaps even allow “OR” to be used in the basic search...just stick to “AND” as default. For example:
apple pear = apple AND pear
apple and pear = apple AND pear
apple or pear = apple OR pear
I could waffle on for ages here, but I wont, I shall just copy and paste my current websites search help info:
Keywords may be separated by AND and/or OR statements for greater control of the search results.
For example, apple AND orange would generate a result set that contain both words. However, for apple OR orange, the result set returned would contain both or either words.
Exact matches can be searched for by enclosing keywords in double-quotes.
For example, “english apple” would generate a result set which match the exact string.
Brackets can be used for further control on the result set.
For example, orange AND (lemon OR banana OR “english apple").
Many thanks in anticipation