我们根据统计信息的详细程度可以设置不同的级别，每种级别见STATS$LEVEL_DESCRIPTION ;

SQL> col DESCRIPTION for a60

SQL> select * from STATS$LEVEL_DESCRIPTION;

SNAP_LEVEL DESCRIPTION

---------- ------------------------------------------------------------

0 This level captures general statistics, including rollback s

egment, row cache, SGA, system events, background events, se

ssion events, system statistics, wait statistics, lock stati

stics, and Latch information

5 This level includes capturing high resource usage SQL Statem

ents, along with all data captured by lower levels

6 This level includes capturing SQL plan and SQL plan usage in

formation for high resource usage SQL Statements, along with

all data captured by lower levels

7 This level captures segment level statistics, including logi

cal and physical reads, row lock, itl and buffer busy waits,

along with all data captured by lower levels

10 This level includes capturing Child Latch statistics, along

with all data captured by lower levels

0：一性性能统计:包含回退段状态、字典缓存、SGA、系统事件、后台事件、会话事件、系统统计、等待统计、锁统计、闩锁统计。

5：增加了收集SQL的信息、并包括0级收集的信息。

6：增强了在SQL收集信息方面的功能(列出占用资源较高的SQL),并包所有低级别的信息。

7：增加了收集段级别的统计信息(如段的逻辑读与物理读、行锁、ITL及buffer busy waits), 并包括所有低级别的信息。

10：增加了收集子LATCH锁的信息,并包括所有低级别的信息。

　　如果你使用statspack确定热表及热索引,那就需要使用7/10的级别来收集快照。默认是5级。

我们可以手工修改这个级别：

永久修改收集级别

SQL> EXEC STATSPACK.MODIFY_STATSPACK_PARAMETER(I_SNAP_LEVEL=>10,I_MODIFY_PARAMETER=>'TRUE');

PL/SQL procedure successfully completed.

临时修改

SQL> EXECUTE STATSPACK.SNAP(I_SNAP_LEVEL=>10);

PL/SQL procedure successfully completed.

ITPub博客

【statspack级别设置】