From: J J
From: Howard Stearns hstearns@wisc.edu That's something I've never really understood: what is the domain in which Relational Databases excel?
Handling large amounts of enterprise data.
Handling and dynamically querying large amounts of data where the data format is not necessarily completely stable and ad-hoc query performance is important. "Large" here is "much larger than main memory of the machine(s) concerned". I routinely handle data sets of tens of gigs on current commodity hardware - storing the data in RAM would be somewhat faster, but too expensive for the available capital.
The strength of relational over other forms is in being able to form arbitrary joins *relatively* efficiently, and hence in being able to query across data many times larger than main memory without excessive disk traffic.
Google isn't a good counter-example, as the ad-hoc querying is missing. The types of queries done on the Google database are very limited and are well known in advance.
- Peter