Overview of search operators by online aggregator

Has anybody ever come across an overview of which various search options (e.g. proximity, similarity search, stemming, etc.) are available in which databases (EBSCO, Oxford, Cambridge, ScjenceDirect, etc.)? And also how the are implemented (e.g. for proximity searches - W10, NEAR/10, etc). It seems to me that a nice overview of these would a) show how backwards some of these search engines still are; and b) be very useful for those of us who often have to go back in the 'help' resources to figure these things out.

[Incidentally, I'd also be interested in finding out why not all providers offer extremely useful full-ext search options like proximity searches. I would have thought that competition would have quickly made all of these things mainstream - but apparently not]
Sign In or Register to comment.