lec13 - Storing Data: Disks and Files Chapter 9 3/6/11 EECS...

Info iconThis preview shows pages 1–5. Sign up to view the full content.

View Full Document Right Arrow Icon
1 3/6/11 EECS 484: Database Management Systems, Kristen LeFevre 1 Storing Data: Disks and Files Chapter 9 3/6/11 EECS 484: Database Management Systems, Kristen LeFevre 2 EECS 484 / 498: Database Implementation Story so far: How do I use a DBMS? Rest of the semester: How does a DBMS work inside? Topics: Storage, disks, and files Indexing and sorting large databases Query evaluation and optimization Transactions, concurrency control, and recovery Hands-On Experience: Minirel2K -- Implement a miniature DBMS 2 Parts: (1) Buffer manager, (2) Query processor Website: http://www.eecs.umich.edu/~klefevre/eecs484
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
2 3/6/11 EECS 484: Database Management Systems, Kristen LeFevre 3 Announcements Written Homework #3 Posted; due in discussion on March 18 Written homework is good practice for exam problems! Graded on a scale of 0-2 Written homeworks to be done on your own! Minirel Project 1: Buffer Manager Posted later today; due March 23 You may work with one partner for programming projects. 3/6/11 EECS 484: Database Management Systems, Kristen LeFevre 4 Today’s Agenda Storage hierarchy (review) Disks (important properties) Buffer management Record formats Page formats (“slotted” pages) File formats
Background image of page 2
3 3/6/11 EECS 484: Database Management Systems, Kristen LeFevre 5 Storage Hierarchy (Review) Tertiary Storage (Tape) Secondary Storage (Magnetic Disk) RAM CPU Cache CPU Primary Storage Volatile Non- Volatile Faster, more expensive Cheaper, slower 3/6/11 EECS 484: Database Management Systems, Kristen LeFevre 6 Magnetic Disk Basics Platters Disk head Arm movement Disk arm Tracks Sector Set of tracks with same diameter called a cylinder Data stored in blocks or pages. (There are usually multiple sectors in a block.) Only one disk head reads or writes at a time.
Background image of page 3

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
4 3/6/11 EECS 484: Database Management Systems, Kristen LeFevre 7 Performance Implications Data stored and retrieved one block at a time Reading or writing a block is called an “I/O” Disk geometry affects the time to perform an I/O • Seek time: time to move disk head to appropriate track • Rotational delay: time waiting for block to move under
Background image of page 4
Image of page 5
This is the end of the preview. Sign up to access the rest of the document.

Page1 / 13

lec13 - Storing Data: Disks and Files Chapter 9 3/6/11 EECS...

This preview shows document pages 1 - 5. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online