[snip]
...big...
[/snip]
We are running OpenBSD servers utilizing a dual Xeon processor
architecture with a 1TB RAID. We have a database using MyISAM
tables...here are some stats from phpMyAdmin on one database on this
server --
20 table(s) Sum 347,092,085 -- 149.6 GB
Two tablea in this database --
tblClass10 128,310,773 MyISAM 40.3 GB
tblClass11 205,420,404 MyISAM 97.4 GB
We do experience delays in performing some complex queries, but even in
these cases MySQL consumes less than 50% of server resources during
processing. We have a set of complex queries that takes approximately
30-45 minutes when run each week, including UPDATES.
Big is only determined by 2 things in my experience, physical resources
and the ability to manage the database well. There are several companies
(Yahoo comes to mind IIRC) that have MySQL databases far larger and more
complex than the ones I use each day.