Physical Data Organization

• mémoire - matière potentielle : management
• mémoire
• mémoire - matière potentielle : db - disk
• mémoire - matière potentielle : block size
• expression écrite

UVA DEPARTMENT OF COMPUTER SCIENCE Physical-1 Physical Data Organization Database design using logical model of the database - appropriate level for users to focus on - user independence from implementation details Performance - other major factor in user satisfaction - depends on - efficient data structures for data representation - efficiency of system operation on those structures Disk access - one of the most critical factors in performance - main memory is in general not big enough for entire DB - recovery problem with main memory DB - disk contains data files and system files including data dictionary and index files

• length records
• system files
• -5 file organization file
• secondary index
• primary storage
• memory block size
• memory - block size
• disk
• block
• files
• data