I once asked if Postgres would have any negative performance impact from holding 1.8m records and once the laughing stopped and they realized I was serious I got a good lesson on how robust Postgres can be.
I once worked for a company that maxed out a 32 bit autoincrement primary key on a mysql table. Relational databases can hold a lot more than people give them credit for.
Yep. I worked at a company that had to migrate to 64-bit IDs. This was with MySQL 5.0 on servers with HDs, not SSD. Some of those "alter table" commands took all night!
