[性能调优] autotrace配置与分析

- sysdba登录系统
sqlplus "/ as sysdba"

- 执行sql
sys@DEMO> @/u01/app/oracle/product/10.2.0/db_1/rdbms/admin/utlxplan.sql

Table created.

- 创建同位语 --- 若存在则报错误信息
sys@DEMO> create public synonym plan_table for plan_table;

create public synonym plan_table for plan_table
                      *
ERROR at line 1:
ORA-00955: name is already used by an existing object

- 赋予public权限
sys@DEMO> grant all on plan_table to public;

- 控制trace产生
-- set autotrace off; --- 不显示，默认设置
-- set autotrace on; --- 显示
-- set autotrace on explain; --- 只显示优化器执行计划
-- set autotrace statistics; --- 只显示统sql计信息
-- set autotrace traceonly; --- 于on相似，但不显示查询结果
-- set autotrace traceonly explain; --- 只显示优化器执行计划(不执行真正查询，所以快)