Just what is 'A big database'?

Question

Ok, dumb question I know but I see the nebulous comment \'a large database\' as well as small and medium and I wonder just what that means. Can someone define what a small, medi

Answer 1

You have to account for hardware advancement for this definition:

1. Small database: working set fits into the physical RAM of a single commodity server (about 16GB now)

2. Medium database: fits into a single or several (through RAID) commodity hard drives on a single machine (up to several TBs now)

3. Large database: Data needs to distributed across multiple commodity servers in order to fit (up to several PBs now.)