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1. Course Intraduction 0
2. Tuning overview 1
(1) 调整的先后次序
1. Tune the design. -- Application designers
2. Tune the application. -- Application developers
3. Tune memory. --|
4. Tune I/O. |-- DBA
5. Tune contention. |
6. Tune the operating system. --|
(2) 调整的基点和主要的可测量的目标
Database hit percentages 命中率是base line
SQL statements access the smallest possible number of Oracle blocks 访问尽可能少的数据块
response time, database availability, memory utilization(页面交换)等
3. Oracle Alert and Trace Files 2
(1) USER_DUMP_DEST和BACKGROUD_DUMP_DEST
USER_DUMP_DEST: SQL_TRACE, DEAD LOCK, 用户session中sql语句的执行情况
BACKGROUD_DUMP_DEST: Alert.log, 系统后台进程的错误信息
(2) Alert.log文件的特性和内容
-- 启动时不存在则自动创建,存在BACKGROUD_DUMP_DEST路径下
-- 文件尺寸一直增长,需要人工清除
-- 包含内容有:
Internal errors (ORA-600), and block corruption errors (ORA-1578)
影响数据库结构,参数的操作,以及命令:CREATE DATABASE, STARTUP, SHUTDOWN, ARCHIVE LOG,RECOVER
实例启动时的非缺省参数 -- 启动时写入 控制文件和在线表空间备份
未完成的检查点
(3) SQL_TRACE设置的两个级别
Instance 参数中设定
Session ALTER SESSION SET SQL_TRACE=TRUE / DBMS_SYSTEM.SET_SQL_TRACE_IN_SESSION(sid,serial#,TRUE/FALSE)
(4) 参数MAX_DUMP_FILE_SIZE限制User Trace文件的O/S Blocks
4. Utilities and Dynamic Performance Views 3
(1) Anylyze执行之后查询信息的字典:
DBA_TABLES and DBA_TAB_COLUMNS table storage within extents and blocks
DBA_HISTOGRAMS and INDEX_HISTOGRAM data about nonindexed and indexed column data distribution.
DBA_INDEXES and INDEX_STATS data about index within extents and blocks and indexation usefulness.
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