11gR2 Performance. Tuning Cookbook. Oracle Database. 1 enterprise J. performance from Oracle Database applications. achieve better

Transcription

1 Oracle Database 11gR2 Performance Tuning Cookbook Over 80 recipes to help beginners achieve better performance from Oracle Database applications Ciro Fiorillo PUBLISHING 1 enterprise J professional expertise distilled BIRMINGHAM - MUMBAI

2 Preface 1 Chapter 1: Starting with Performance Tuning 7 Introduction 7 Reviewing the performance tuning process 12 Exploring the example database 17 Acquiring data using a data dictionary and dynamic performance views 20 Analyzing data using Statspack reports 23 Diagnosing performance issues using the alert log 28 Analyzing data using Automatic Workload Repository (AWR) 29 Analyzing data using Automatic Database Diagnostic Monitor (ADDM) 32 A working example 36 Chapter 2: Optimizing Application Design 41 Introduction 41 Optimizing connection management 42 Improving performance sharing reusable code 48 Reducing the number of requests to the database using stored procedures 54 Reducing the number of requests to the database using sequences 59 Reducing the number of requests to the database using materialized views 65 Optimizing performance with schema denormalization 71 Avoiding dynamic SQL 79 Chapter 3; Optimizing Storage Structures 83 Introduction 83 Avoiding row chaining 84 Avoiding row migration 89 Using LOBs 96 Using index clusters 103 Using hash clusters 109 Indexing the correct way 113

3 Rebuilding index 123 Compressing indexes 128 Using reverse key indexes 130 Using bitmap indexes 136 Migrating to index organized tables 142 Using partitioning 146 Chapter 4: Optimizing SQL Code 153 Introduction 153 Using bind variables 154 Avoiding full table scans 164 Exploring index lookup 173 Exploring index skip-scan and index range-scan 177 Introducing arrays and bulk operations 181 Optimizing joins 187 Using subqueries 192 Tracing SQL activity with SQL Trace and TKPROF 201 Chapter 5: Optimizing Sort Operations 207 Introduction 207 Sorting in-memory and on-disk 208 Sorting and indexing 215 Writing top n queries and ranking 224 Using count, min/max, and group-by 232 Avoiding sorting in set operations: union, minus, and intersect 240 Troubleshooting temporary tablespaces 248 Chapter 6: Optimizing PL/SOL Code 253 Introduction 253 Using bind variables and parsing 254 Array processing and bulk-collect 257 Passing values with NOCOPY (or not) 262 Using short-circuit IF statements 266 Avoiding recursion 269 Using native compilation 271 Taking advantage of function result cache 276 Inlining PL/SQL code 281 Using triggers and virtual columns 284 Chapter 7: Improving the Oracle Optimizer 291 Introduction 291 Exploring optimizer hints 292 Collecting statistics 298 Using histograms 305 -

4 Managing stored outlines 310 Introducing Adaptive Cursor Sharing for bind variable peeking 317 Creating SQL Tuning Sets 327 Using the SQL Tuning Advisor 331 Configuring and using SQL Baselines 335 Chapter 8: Other Optimizations 341 Introduction 341 Caching results with the client-side result cache 342 Enabling parallel SQL 346 Direct path inserting 351 Using create table as select 355 Inspecting indexes and triggers overhead 359 Loading data with SQL*Loader and Data Pump 366 Chapter 9: Tuning Memory 375 Introduction 375 Tuning memory to avoid Operating System paging 376 Tuning the Library Cache 384 Tuning the Shared Pool 388 Tuning the Program Global Area and the User Global Area 396 Tuning the Buffer Cache 400 Chapter 10: Tuning I/O 411 Introduction 411 Tuning at the disk level and strategies to distribute Oracle files 412 Striping objects across multiple disks 419 Choosing different RAID levels for different Oracle files 422 Using asynchronous I/O 425 Tuning checkpoints 428 Tuning redo logs 433 Chapter 11: Tuning Contention 437 Introduction 437 Detecting and preventing lock contention 438 Investigating transactions and concurrency 444 Tuning latches 452 Tuning resources to minimize latch contention 457 Minimizing latches using bind variables 460 Appendix A: Dynamic Performance Views 469 ALL_OBJECTS 469 DBA_BLOCKERS 470 DBA_DATA_FILES 470 qsti_

5 DBA_EXTENTS 471 DBAJNDEXES 471 DBA_SQL_PLAN_BASELINES 472 DBA.TABLES 472 DBA_TEMP_FILES 473 DBA.VIEWS 474 DBA.WAITERS 474 INDEX_STATS 474 DBA.SEQUENCES 475 DBA.TABLESPACES 476 DBA_TAB_HISTOGRAMS 476 V$ADVISOR_PR0GRESS 477 V$BUFFER_POOL_STATISTICS 477 V$CONTROLFILE 478 V$DATAFILE 478 V$DB_CACHE_ADVICE 479 V$DB_OBJECT_CACHE 480 V$ENQUEUE_LOCK 480 V$FILESTAT 481 V$FIXED_TABLE 482 V$INSTANCE_RECOVERY 482 V$LATCH 483 V$LATCH_CHILDREN 433 V$LIBRARYCACHE 434 V$LOCK 485 V$LOCKED_OBJECT 486 V$LOG 486 V$LOG_HISTORY 437 V$LOGFILE 488 VSMYSTAT 488 V$PROCESS 489 V$ROLLSTAT 489 VSROWCACHE 490 V$SESSION 490 V$SESSION_EVENT 491 V$SESSTAT 492 V$SGA 492 V$SGAINFO 493 V$SHARED_POOL_RESERVED 493 V$SORT_SEGMENT 494 V$SQL 494 -DH

6 V$SQL_PLAN 495 V$SQLAREA 496 V$STATNAME 496 V$SYSSTAT 497 V$SYSTEM_EVENT 498 V$TEMPFILE 498 V$TEMPSTAT 499 V$WAITSTAT 499 X$BH 500 Appendix B: A Summary of Oracle Packages Used for Performance Tuning 501 DBMS_ADDM 501 DBMS.ADVISOR 502 DBMSJOB 502 DBMS_LOB 503 DBMS_MVIEW 503 DBMS_OUTLN 503 DBMS_OUTLN_EDIT 504 DBMS_SHARED_POOL 504 DBMS_SPACE 505 DBMS_SPM 505 DBMS_SQL 505 DBMS_SQLTUNE 506 DBMS_STATS 506 DBMS_UTILITY 507 DBMS_WORKLOAD_REPOSITORY 507 Index 509 DD