SEMANTEC 1 Oracle Performance Tuning - Part I Krasen Paskalev Oracle 8i Certified DBA

SEMANTEC2 Why are we here? (The list is generated by the participants input.)  Gain More knowledge  Make work better  Satisfy the customers‘ requests for performance tiuning  Proactive tuning  Learn methods for performance bottleneck identification

SEMANTEC3 Why Oracle performance tuning is important?  The Oracle database is different from the competing products!  Our customers and our competition cannot do it.

SEMANTEC4 Oracle and otherwise

SEMANTEC5 Oracle inside

SEMANTEC6 Oracle has many „switches“ allowing to tune its work. But how to use them?  To be a good tuner you need:  Knowledge  Understanding  Experience

SEMANTEC7 Agenda:  Roles associated with tuning  What is being tuned. Trade-offs in tuning  Tuning steps and methods  Tuning goals  Common guidelines

SEMANTEC8 Roles associated with tuning  Users – identify  Developers – change code  DBA, SA – find bottleneck, reconfigure  Management – change organisation, give money

SEMANTEC9 Application Performance Good Poor Non criticalMission critical Organisation‘s dependence on application Will be resolved May be resolved if budget permits Probably won‘t be resolved Organisation tuning budget

SEMANTEC10 What is being tuned?  Response time  Throughput  Wait time  Critical resources – CPU, Memory, I/O, Network

SEMANTEC11 Tuning steps  Business rules  Design and Architecture– data and application  Application – SQL, PL/SQL

SEMANTEC12 Tuning steps - continued  Memory structures  Disk I/O usage  Resource contention  OS  Hardware

SEMANTEC13 Tuning goals  Tune SQL statement  Tune process  Tune specific application  Tune all applications in an instance

SEMANTEC14 Common guidelines  Set clear tuning goals – define success  Create repeatable mesurable tests  Try to automate  Keep records  Test hypothesys

SEMANTEC15 Avoid common errors  Test hypothesys one at a time  Consult the tuning measures in a team  Don‘t guess – prove by test  Ask users to describe problems – not to explain them  Stop when objectives are met – or a little later

SEMANTEC16 What next? (The list is generated by the participants input.)  Oracle optimizer  Memory structures, Process structures, Manage Oracle processes  Explain plan, access paths, Join methods  Oracle configuration options – initialization parameters.  Design for performance  Indexes  Parallel execution  Oracle specific feature for tuning  Physical design and layout  Connection pooling (Networking)