Database Page each Database Page is given a unique identifier; a page ID could be unique per DBMS, per DB, or per table—page IDs is indirection to physical location. a Database Page is a fixed-size block of data tuples meta-data indicies log records … most systems do not mix page types (don’t mix different tables, do not mix different types, etc.) some systems require a page to be self contained (no pointers, etc.) — for fault tolerance Whoops, we accidentally overloaded a word Hardware Page (4kb, i.e. a block on the physical disk) OS Page (usually a block, notionally different for now but abstracted, 2mb, 1gb) Database Page each Database Page is automatically read/written