Tuple layout

A tuple is essentially a sequence of byte

It's the job of DBMS to interpret those bytes into attribute type and values

Tuple header

Each tuple is prefixed of a header that contains metadata about it

• Visible info (concurrency control)

• Bit map for NULL values

We do not need to store metadata about the schema.

Tuple data

Attributes are typically stored in the order that you specify them when you create the table

This is done for software engineering reasons

We re-order attributes automatically in CMU's new DBMS...