Download Database Tuning Principles, Experiments and Troubleshooting

CS 5226: Database
Administration and Performance
Tuning
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Course Structure
• Continuous Assessment: 50%
– Assignments: 25%
– Lab Sessions: 25%
• Lecturers:
– Prof. Ooi Beng Chin (ooibc)
– DBAs: Sze Eng Koon and Phillip Lim
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Text/Reference Books:
• Dennis Shasha and Phillipe Bonnet: Database Tuning : Principles
Experiments and Troubleshooting Techniques. Morgan Kaufmann
Publishers. 2002 (released in June 2002). TEXT.
• Dennis Shasha: Database tuning : a principled approach. Prentice Hall,
1992. REFERENCE (a good reference if cannot get the text book)
• Database Management Systems, 3rd edition. Raghu Ramakrishnan &
Johannes Gehrke, McGraw-Hill, 2002.
• Hector Garcia-Molina, Jeffrey D. Ullman, and Jennifer Widom:
Database Systems -- The Complete Book. Prentice Hall, 2001.
• G. J. Vaidyanatha, K. Deshpande and J. Kostelac: Oracle Performance
Tuning 101. Osborne/Mc-Graw-Hill. 2001. REFERENCE.
• Jim Gray (ed): The Benchmark handbook : for database and
transaction processing systems. M. Kaufmann Publishers, 1991.
REFERENCE.
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Copyright:
Many slides belong to the tutorial:
Database Tuning
Principles, Experiments and Troubleshooting Techniques
Dennis Shasha ([email protected])
Philippe Bonnet ([email protected])
And lecture notes provided by
Database Management Systems, 3rd edition.
Raghu Ramakrishnan & Johannes Gehrke
McGraw-Hill, 2002.
and some from the web …
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Database Tuning
Database Tuning is the activity of making a
database application run more quickly.
“More quickly” usually means higher
throughput, though it may mean lower
response time for time-critical applications.
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Application
Programmer
(e.g., business analyst,
Data architect)
Application
Sophisticated
Application
Programmer
Query Processor
(e.g., SAP admin)
Indexes
Storage Subsystem
Concurrency Control
Recovery
DBA,
Tuner
Operating System
Hardware
[Processor(s), Disk(s), Memory]
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Goals of the Course
• Appreciation of DBMS architecture
• Study the effect of various components on
the performance of the systems
• Tuning principles
• Troubleshooting techniques for chasing
down performance problems
• Hands-on experience in Tuning
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Contents
1.
2.
3.
4.
5.
6.
7.
8.
9.
Basic Principles
Tuning the guts
Indexes
Relational Systems
Application Interface
E-commerce Applications
Data warehouse Applications
Distributed Applications
Troubleshooting
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Tuning Principles
• Think globally, fix locally
– Localizing the problems
• Partitioning breaks bottlenecks (temporal
and spatial)
– ONE part of the system limits the the overall
performance
– Two approaches:
• Fix locally
• Partitioning the LOAD
– eg. Free list, lock contention due to long transactions
• Partitioning in space/logical resources/time9
Tuning Principles
• Start-up costs are high; running costs are
low
– Start-up costs include
•
•
•
•
Disk access
Data transfer
Query processing
System calls
– Reduce the number of start-ups
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An example:
Time =
Rule of
Thumb
Seek Time +
Rotational Delay +
Transfer Time +
Other
Random I/O: Expensive
Sequential I/O: Much less
• Ex:1 KB Block
» Random I/O:  20 ms.
» Sequential I/O:  1 ms.
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Tuning Principles
• Render onto server what is due onto Server
– Task allocation between the server and the
application programs
– Factors:
• Relative computing resources of client, application
servers and data server
– Should checking be done in the middle tier?
• Location of information
• The nature of tasks: interaction with screen?
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Tuning Principles
• Be prepared for trade-offs
• Ex. Indices
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Tuning Mindset
1.
2.
3.
4.
5.
Set reasonable performance tuning goals
Measure and document current performance
Identify current system performance bottleneck
Identify current OS bottleneck
Tune the required components eg: application,
DB, I/O, contention, OS etc
6. Track and exercise change-control procedures
7. Measure and document current performance
8. Repeat step 3 through 7 until the goal is met
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