[Database] Disk Representations: Files, Pages, Records

Tables stored as logical files • Consist of pages

• Pages contain a collection of records Pages are managed
• On disk by the disk space manager: pages read/written to physical disk/files
• In memory by the buffer manager:
  higher levels of DBMS only operate in memory

DataBase Files

DB Files : A collection of pages, each containing a collection.

Unordered Heap Files

• Records placed arbitrarily across pages Clustered Heap Files
• Records and pages are grouped Sorted Files
• Pages and records are in sorted order
  Index Files
• B+ Trees, Linear Hashing, ...
• May contain records or point to records in other files

Unordered Heap Files

collection of recording in particular order , but not to be confused wi the heap data structure.
Keep track of record, free space and pages.

Heap File implemented as List

doubly list

Comparison of different file type