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Oracle11g SQL
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SQL Performance Analyzer
forecast the impact of a potential change on the performance of a SQL query workload.
• Database upgrades• Implementation of tuning recommendations• Schema changes• Statistics gathering• Database parameter changes• OS/hardware changes
might be
reported for as a Tuning Result
WHEN?
SQL Performance Analyzer
Extract STS(SQL Tuning Set) from production
FROM Cursor Cache– SQL Text– Bind variables– Execution plans– Execution statistics
What’s inside?
- Incremental capture over a time period
- filtering and ranking capabilities filters out undesirable SQL
FILTERINGAlways all? No!
SQL Performance Analyzer
Transport to a test system (STS COPY)
SQL Performance = execution plans + execution statistics
• Test-Execute SQL– produce execution plans and statistics– execute SQL serially– every SQL is executed only once• Explain plan SQL in SQL tuning set to generate SQL plans only
변 경 전 변 경 후
Execute Re-Execute
SQL Performance Analyzer
SQL Performance = execution plans + execution statistics
And nextDetect - improvements - regressions - unchanged performance - changes in execution plans
Tune - regressed SQLs - index
Choose - SQL Plan Management baseline
XO?
SQL Performance Analyzer
SQL Performance = execution plans + execution statistics
DoCreating a SQL Tuning Set (Capturing the SQL Workload) Sources - Cursor Cache - AWR Snapshots, Baselines - User-defined Workload (sql_text, parsing_schema_name col-umns)
Exporting the SQL Workload - choose to export the selected STS - load a STS on the test system for comparison purposes
Collect SQL Performance
Change - parameter - index - hint
SQL Performance Analyzer
SQL Performance = execution plans + execution statistics
Do DoCollect SQL Performance
Compare SQL Performance
Analysis Results - before vs after
Using EM
SQL Performance Analyzer
SQL Performance = execution plans + execution statistics
Do Do DoDBMS_SQLTUNE
- CREATE_TUNING_TASK
- EXECUTE_TUNING_TASK
- REPORT_TUNING_TASK
- etc………………
To be continued………………