[20210926]DBA_HIST_SQLSTAT.ELAPSED_TIME_DELTA的单位.txt

[20210926]DBA_HIST_SQLSTAT.ELAPSED_TIME_DELTA的单位.txt --//记录一下自己一个错误,把DBA_HIST_SQLSTAT.ELAPSED_TIME_DELTA的单位搞错了,这样前面awr报表遇到的问题许多就很好解析了.. --//前几天awr分析,遇到一些我无法理解的问题,测试看看.DBA_HIST_SQLSTAT.ELAPSED_TIME_DELTA的单位是什么. 1.环境: SCOTT@book> @ ver1 PORT_STRING                    VERSION        BANNER ------------------------------ -------------- -------------------------------------------------------------------------------- x86_64/Linux 2.4.xx            11.2.0.4.0     Oracle Database 11g Enterprise Edition Release 11.2.0.4.0 - 64bit Production 2.测试: SCOTT@book> select count(*) from emp,emp,emp,emp,emp,emp,emp;   COUNT(*) ----------  105413504 SCOTT@book> set timing on SCOTT@book> select count(*) from emp,emp,emp,emp,emp,emp,emp;   COUNT(*) ----------  105413504 Elapsed: 00:00:04.26 SCOTT@book> select count(*) from emp,emp,emp,emp,emp,emp,emp;   COUNT(*) ----------  105413504 Elapsed: 00:00:04.22 --//执行3次总共消耗12.XX秒上下. SCOTT@book> @ hash HASH_VALUE SQL_ID        CHILD_NUMBER HASH_HEX ---------- ------------- ------------ --------- 2779624423 gau6fcukuvcz7            0  a5adb3e7 Elapsed: 00:00:00.04 SCOTT@book> @ cr_s PL/SQL procedure successfully completed. --//生成awr snap. Elapsed: 00:00:00.92 SCOTT@book> @ sqlh gau6fcukuvcz7 0 @ sqlh  sql_id [snap_id]    SNAP_ID INSTANCE_NUMBER PLAN_HASH_VALUE BEGIN_INTERVAL_TIME      END_INTERVAL_TIME        ELAPSED_TIME_DELTA CPU_TIME_DELTA EXECUTIONS_DELTA EXECUTIONS_TOTAL ROWS_PROCESSED_DELTA BUFFER_GETS_DELTA LOADED_VERSIONS ---------- --------------- --------------- ------------------------ ------------------------ ------------------ -------------- ---------------- ---------------- -------------------- ----------------- ---------------       4177               1      2048615215 2021-09-26 11:00:22.918  2021-09-26 11:12:09.053            12733395       12705068                3                3                    3               115               1 Elapsed: 00:00:00.02 --//噢,我前面搞错了,单位应该是微秒不是毫秒. SCOTT@book> @ tpt/sql_id gau6fcukuvcz7 % Show SQL text, child cursors and execution stats for SQLID gau6fcukuvcz7 child % HASH_VALUE  CH# SQL_TEXT ---------- ---- ------------------------------------------------ 2779624423    0 select count(*) from emp,emp,emp,emp,emp,emp,emp Elapsed: 00:00:00.03  CH# PARENT_HANDLE    OBJECT_HANDLE     PLAN_HASH     PARSES   H_PARSES EXECUTIONS    FETCHES ROWS_PROCESSED     CPU_MS     ELA_MS       LIOS       PIOS      SORTS USERS_EXECUTING ---- ---------------- ---------------- ---------- ---------- ---------- ---------- ---------- -------------- ---------- ---------- ---------- ---------- ---------- ---------------    0 000000007DD4DCF0 000000007CD9A9C0 2048615215          3          1          3          3              3  12705.068  12733.395        115          3         18               0 --//12733395/10^6 = 12.733395秒,看来我前面的测试时间搞错了,不是毫秒.而是微秒. https://docs.oracle.com/cd/B19306_01/server.102/b14237/statviews_3183.htm#REFRN23447 ELAPSED_TIME_DELTA  NUMBER   Delta value of elapsed time (in microseconds) used by this cursor for parsing/executing/fetching --//金山词霸的查询结果. microsecond [5maIkrEJsekEnd] n 微秒，百万分之一秒 microsecond [5maIkrEJsekEnd] n.一百万分之一秒, 微秒 --//不知道为什么看到micro,第一反应是毫,实际上这个表示微. 毫秒的英文是 millisecond.