deadlock

From: Barbara Baker <barb.baker_at_gmail.com>
Date: Wed, 27 Mar 2013 12:43:15 -0600
Message-ID: <CAMCQWTMTPR4pgG=MJWZia15XjtvpOQ6XfjbUJD9+FLtPL=RWGQ_at_mail.gmail.com>

10.2.0.1.1 database on windows. Response is slow. Application seems to be a piece of crap.
I set trace on for his session, and he re-enacted the "slowness" Details of the deadlock are below. After I traced the session and explained to the developer that his code created a deadlock when it should not have, here's what I got back from him: Barb,****

• **

    I do not want to explain how deadlock works/happens but that is not the cause for slow response. If you get a deadlock situation between two sessions, Oracle automatically terminates one of the sessions immediately and allows other session to continue. Deadlock does not slow down the database response but it does terminates one of the sessions involved in the deadlock.

He further went on to explain that the deadlock would be frequent because the database is slow. He's trying to talk me into exporting the entire database and then re-importing it.

Show of hands: who thinks it is good development to lock a table on a select and then allow Oracle to terminate one of the sessions??

(Extra points to Oracle for putting in the caveat about the deadlock directly into the trace file!!)

• SESSION ID:(284.4872) 2013-02-25 09:55:29.715

DEADLOCK DETECTED [Transaction Deadlock]

Current SQL statement for this session:

SELECT * FROM LOC WHERE LOC = :B1 FOR UPDATE

• PL/SQL Call Stack -----

  object line object

  handle number name

46FD56A8 330 package body MTC.S2P_LOC

46FD56A8 346 package body MTC.S2P_LOC

46FD56A8 296 package body MTC.S2P_LOC

4BA81DC0 513 package body MTC.S2P_ROUTE

4682AC10 840 package body MTC.S2P_TASKTRN_CTL

46C6CBD8 193 MTC.S2T_TASKTRN_IAS 4BBDF384 64 package body MTC.S2P_TASKTRN

4BBDF384 1786 package body MTC.S2P_TASKTRN

4B9903AC 115 package body MTC.S2P_RF_TASK

4B9903AC 2198 package body MTC.S2P_RF_TASK

4B976B1C 1 anonymous block

The following deadlock is not an ORACLE error. It is a

deadlock due to user error in the design of an application

or from issuing incorrect ad-hoc SQL. The following

information may aid in determining the deadlock:

Deadlock graph:

                       ---------Blocker(s)--------

---------Waiter(s)---------

Resource Name process session holds waits process session holds waits

TX-00040012-00041544 30 *284* X 15 *319* X

TX-0003001c-00041519 15 *319* X 30 *284* X

session 284: DID 0001-001E-000E178A session 319: DID 0001-000F-037146D9

session 319: DID 0001-000F-037146D9 session 284: DID 0001-001E-000E178A

Rows waited on:

Session 319: obj - rowid = 0000F34E - AAAPNOAAFAAAAInAAA

(dictionary objn - 62286, file - 5, block - 551, slot - 0)

Session 284: obj - rowid = 0000F34E - AAAPNOAAFAAAAInAAJ

(dictionary objn - 62286, file - 5, block - 551, slot - 9)

Information on the OTHER waiting sessions:

Session 319:

  pid=15 serial=64939 audsid=0 user: 57/MTC

  O/S info: user: SYSTEM, term: HKWMSN01, ospid: 2476, machine: HKWMSN01

            program: ORACLE.EXE (J000)

  Current SQL information unavailable

End of information on OTHER waiting sessions.

--
http://www.freelists.org/webpage/oracle-l

Received on Wed Mar 27 2013 - 19:43:15 CET