11g nf sql_anlz
Download as PPTX, PDF0 likes312 views
This document discusses SQL Performance Analyzer and how it can be used to forecast the impact of potential database changes on the performance of SQL queries. It extracts a SQL Tuning Set (STS) from production, transports it to a test system, re-executes the SQL after applying changes, detects any performance improvements, regressions or plan changes, and allows tuning of regressed SQL queries.
11g nf sql_anlz
- 2. SQL Performance Analyzer forecast the impact of a potential change on the performance of a SQL query workload.WHEN?• Database upgrades• Implementation of tuning recommendations• Schema changes• Statistics gathering• Database parameter changes• OS/hardware changes might be reported for as a Tuning Result
- 3. SQL Performance AnalyzerExtract STS(SQL Tuning Set) from productionWhat’s inside?FROM Cursor Cache– SQL Text– Bind variables– Execution plans– Execution statistics- Incremental capture over a time period- filtering and ranking capabilities filters out undesirable SQLFILTERINGAlways all? No!
- 4. SQL Performance AnalyzerTransport to a test system (STS COPY)변 경 전변 경 후ExecuteRe-Execute• 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 onlySQL Performance = execution plans + execution statistics
- 5. SQL Performance AnalyzerAnd nextDetect - improvements - regressions - unchanged performance - changes in execution plansTune - regressed SQLs - indexChoose - SQL Plan Management baselineXO?SQL Performance = execution plans + execution statistics
- 6. SQL Performance AnalyzerDoCreating a SQL Tuning Set (Capturing the SQL Workload) Sources - Cursor Cache - AWR Snapshots, Baselines - User-defined Workload (sql_text, parsing_schema_name columns)Exporting the SQL Workload - choose to export the selected STS - load a STS on the test system for comparison purposesCollect SQL PerformanceChange - parameter - index - hintSQL Performance = execution plans + execution statistics
- 7. SQL Performance AnalyzerDo DoCollect SQL PerformanceCompare SQL PerformanceAnalysis Results - before vs afterUsing EMSQL Performance = execution plans + execution statistics
- 8. SQL Performance AnalyzerDo DoDoDBMS_SQLTUNE - CREATE_TUNING_TASK - EXECUTE_TUNING_TASK - REPORT_TUNING_TASK - etc………………To be continued………………SQL Performance = execution plans + execution statistics