详解Oracle 数据库中的事务数及长事务常用sql

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。

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;

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;

官网：

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

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

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~