Standard use of 'Z' instead of NULL to represent missing data?

Question

Outside of the argument of whether or not NULLs should ever be used: I am responsible for an existing database that uses NULL to mean "missing or never entered" da

Answer 1

In reply to contractors comments

• Empty string <> NULL
• Empty string requires 2 bytes storage + an offset read
• NULL uses null bitmap = quicker
• IDENTITY doesn't always start at 1 (why waste half your range?)

The whole concept is flawed as per most other answers here