sqlserverscience.com
How SQL Server Packs BIT Columns Into a Single Byte
A common worry about bit columns is that a table full of yes/no flags will waste a byte on every flag. It will not. SQL Server packs bit columns together, up to eight of them sharing a single byte, and the catalog view that reports each bit as "1 byte" hides that fact rather than revealing it. This is a short, satisfying one to see on the page: we will store ten…