I have diagnosed a deadlock problem in my sql server using the deadlock graph in SQL Server 2008.
The problem has to do with my indexes. I have two queries: a long running report with alot of joins and subqueries that pulls data according to two different dates on a base table, and a quick update query, which updates those same dates on that base table. I have two indexes, and the report wants a shared KEY lock on both of them, while the update query wants an exclusive KEY lock on both of them, and somehow each query only manages to get one of the keys, so neither can proceed.
What can I do to fix this?
Here's all the details on my situation:
My base table looks like this:
CREATE TABLE job_tb{
job_id int IDENTITY(1,1),
createDate datetime NULL,
upDate datetime NULL,
dataField1 nchar(1),
dataField2 nchar(2),
--etc...
}
My indices look like this:
CREATE NONCLUSTERED INDEX idx_createDate ON job_tb(
createDate DESC
)
INCLUDE(dataField1, dataField2)
CREATE NONCLUSTERED INDEX idx_upDate ON job_tb(
upDate DESC
)
INCLUDE(dataField1, dataField2)
Lastly, my update looks like this:
BEGIN TRANSACTION;
UPDATE job_tb
SET
dataField1 = @data
upDate = @upDate
WHERE
job_id = @job_id
COMMIT TRANSACTION;
And the report is counting all kinds of statistics by date, so I won't include that here. I intentionally designed idx_createDate and idx_upDate to "cover" or include dataField1, since it's heavily used in that report.
I believe the report grabs a shared lock on one of the indexes, then hits a subquery and requests a lock on the second index. Meanwhile the update query wants an exclusive lock on both indices in order to update both the upDate and the included dataField1.
What do you guys think?
EDIT: Here's the XML deadlock graph, as requested:
<deadlock-list> <deadlock>
<victim-list>
<victimProcess id="processcf65288"/>
</victim-list>
<process-list>
<process id="processcf65288" taskpriority="0" logused="0" waitresource="KEY: 6:72057597970874368 (eee1799e706c)" waittime="122" ownerId="421742704" transactionname="SELECT" lasttranstarted="2012-08-03T05:37:21.257" XDES="0x8611e8800" lockMode="S" schedulerid="50" kpid="8560" status="suspended" spid="70" sbid="0" ecid="0" priority="0" trancount="0" lastbatchstarted="2012-08-03T05:37:21.257" lastbatchcompleted="2012-08-03T05:37:21.257" clientapp="Internet Information Services" hostname="xxx" hostpid="11964" loginname="xxx" isolationlevel="read committed (2)" xactid="421742704" currentdb="6" lockTimeout="4294967295" clientoption1="671088672" clientoption2="128056">
<executionStack>
<frame procname="" line="28" stmtstart="1276" stmtend="4826" sqlhandle="0x03000600311ac36c65a31701a1a000000100000000000000">
</frame>
<frame procname="" line="1" sqlhandle="0x01000600f61bee3600932ae3090000000000000000000000">
</frame>
</executionStack>
<inputbuf> exec MonthlyReport @id = 41
</inputbuf>
</process>
<process id="processd2b6bc8" taskpriority="0" logused="1908" waitresource="KEY: 6:72057597970939904 (8e8117a49479)" waittime="2242" ownerId="421742551" transactionname="user_transaction" lasttranstarted="2012-08-03T05:37:20.447" XDES="0x7e84ad0a0" lockMode="X" schedulerid="63" kpid="12700" status="suspended" spid="89" sbid="0" ecid="0" priority="0" trancount="2" lastbatchstarted="2012-08-03T05:37:20.443" lastbatchcompleted="2012-08-03T05:37:20.443" clientapp="Internet Information Services" hostname="xxx" hostpid="11964" loginname="xxx" isolationlevel="read committed (2)" xactid="421742551" currentdb="6" lockTimeout="4294967295" clientoption1="673185824" clientoption2="128056">
<executionStack>
<frame procname="" line="47" stmtstart="2342" stmtend="2640" sqlhandle="0x03000600e7dd9c717cbbb900ec9f00000100000000000000">
</frame>
<frame procname="" line="1" sqlhandle="0x01000600311d7a152032f9be040000000000000000000000">
</frame>
</executionStack>
<inputbuf> exec UpdateJob @dataField1 = 'C', @upDate = '8/3/2012 5:37:20 AM', @job_id = 1542687
</inputbuf>
</process>
</process-list>
<resource-list>
<keylock hobtid="72057597970874368" dbid="6" objectname="" indexname="" id="lock612859900" mode="X" associatedObjectId="72057597970874368">
<owner-list>
<owner id="processd2b6bc8" mode="X"/>
</owner-list>
<waiter-list>
<waiter id="processcf65288" mode="S" requestType="wait"/>
</waiter-list>
</keylock>
<keylock hobtid="72057597970939904" dbid="6" objectname="" indexname="" id="lock612a15300" mode="S" associatedObjectId="72057597970939904">
<owner-list>
<owner id="processcf65288" mode="S"/>
</owner-list>
<waiter-list>
<waiter id="processd2b6bc8" mode="X" requestType="wait"/>
</waiter-list>
</keylock>
</resource-list>
</deadlock> /deadlock-list>
begin transaction
? – Fraisebegin transaction
– Mosul