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