概述

在数据库中事务是工作的逻辑单元，一个事务是由一个或多个完成一组的相关行为的SQL语句组成，通过事务机制确保这一组SQL语句所作的操作要么都成功执行，完成整个工作单元操作，要么一个也不执行。

如果要查询当前事务我们可以查询v$transaction表获得相关信息，查一段时间的事务数可以通过awr报告中的Transactions和user commits来得知，不过今天主要介绍怎么用sql来查询事务数。

1、查询XX时间段每秒事务数

select instance_number,
 metric_unit,
 trunc(begin_time) time,
 round(avg(average), 2) average
 from DBA_HIST_SYSMETRIC_SUMMARY
 where metric_unit = 'Transactions Per Second'
 and begin_time >=
 to_date('2019-10-09 00:00:00', 'yyyy-mm-dd hh24:mi:ss')
 and begin_time < to_date('2019-10-09 14:00:00', 'yyyy-mm-dd hh24:mi:ss')
 group by instance_number, metric_unit, trunc(begin_time)
 order by instance_number;

2、查询XX时间段每天事务数

select instance_number,
 metric_unit,
 trunc(begin_time) time,
 avg(average) * 60 * 60 * 24 "Transactions Per Day"
 from DBA_HIST_SYSMETRIC_SUMMARY
 where metric_unit = 'Transactions Per Second'
 and begin_time >=
 to_date('2019-10-01 00:00:00', 'yyyy-mm-dd hh24:mi:ss')
 and begin_time < to_date('2019-10-09 00:00:00', 'yyyy-mm-dd hh24:mi:ss')
 group by instance_number, metric_unit, trunc(begin_time)
 order by instance_number;

3、查询某个用户事务数

官网：

DeltaCommits + DeltaRollbacks where:

• DeltaCommits: difference of 'select value from v$sysstat where name='user commits'' between sample end and start
• DeltaRollbacks: difference of 'select value from v$sysstat where name='user rollbacks'' between sample end and start

在2个时间段分别执行上面语句，把2个结果相减即可得出这段时间内的事务数。根据这个方法，我写出查询某个用户的时间段内事务数的方法：

select s.USERNAME,
 sum(se.VALUE) "session transaction number",
 sum(sy.VALUE) " database transaction number"
 from v$session s, v$sesstat se, v$sysstat sy
 where s.sid = se.SID
 and se.STATISTIC# = sy.STATISTIC#
 and sy.NAME = 'user commits'
 and s.USERNAME = upper('&username')
 group by s.USERNAME;

使用方法和上面的一样，需要在2个时间段分别运行改脚本，把执行结果相减，即可得出该时间段内的事务数

4、查询当前正在执行的事务

SELECT s.sid,
 s.serial#,
 s.event,
 a.sql_text,
 a.sql_fulltext,
 s.username,
 s.status,
 s.machine,
 s.terminal,
 s.program,
 a.executions,
 s.sql_id,
 p.spid,
 a.direct_writes
 FROM (SELECT * FROM v$session WHERE status = 'ACTIVE') s
 LEFT JOIN v$sqlarea a
 ON s.sql_id = a.sql_id
 INNER JOIN v$process p
 ON s.paddr = p.addr

5、查询长事务

with transaction_details as
( select inst_id
 , ses_addr
 , sysdate - start_date as diff
 from gv$transaction
)
select s.username
, to_char(trunc(t.diff))
 || ' days, '
 || to_char(trunc(mod(t.diff * 24,24)))
 || ' hours, '
 || to_char(trunc(mod(t.diff * 24 * 60,24)))
 || ' minutes, '
 || to_char(trunc(mod(t.diff * 24 * 60 * 60,60)))
 || ' seconds' as transaction_duration
, s.program
, s.terminal
, s.status
, s.sid
, s.serial#
from gv$session s
, transaction_details t
where s.inst_id = t.inst_id
and s.saddr = t.ses_addr
order by t.diff desc

觉得有用的朋友多帮忙转发哦！后面会分享更多devops和DBA方面的内容，感兴趣的朋友可以关注下~