Remember, it's just a rule of thumb. Now... tables with 2 32-bit ints as columns are not exactly typical RDBMS data. Also, data in RDBMS are... well relational

Remember, it's just a rule of thumb. Now... tables with 2 32-bit ints as columns are not exactly typical RDBMS data. Also, data in RDBMS are... well relational :) Meaning, the rows of just one table are not that important. The data are going to be queried and combined with data from other tables. And I know that typical relational data that consist of hundreds of millions of entries in each table is something that most DBs can handle. Again, rule of thumb :D