I have an upcoming interview for a position at a company that deals with multi-petabyte scale data volumes. They're going to grill me about standard database design questions, but what are the best things to focus my revision/prep work on? How does database design change when you get to really gigantic scales?
I currently think about:
- Indexes fitting in memory
- In transactional tables (e.g. ad clickstream) splitting the data up into 1 table per month, or having a "recent" and "historical" set of tables with a flushing job every night or week.
- Over-normalization - unnecessary primary keys and dimensions (such as a separate table for US zipcodes).
Any suggestions appreciated