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rajasekar2810
New User
Joined: 22 Apr 2008 Posts: 6 Location: india
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Hi
Can any one tell me about what is LTXNLOCK concept in IDMS DB. |
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nelson.pandian
Active User
Joined: 09 Apr 2008 Posts: 133 Location: Phoenix, AZ
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Hallo
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Can any one tell me about what is LTXNLOCK concept in IDMS DB.
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From were did you find this LTXNLOCK????? |
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enrico-sorichetti
Superior Member
Joined: 14 Mar 2007 Posts: 10872 Location: italy
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maybe in a deadlock message ??
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DC001000 T:20425 ADS2 P:DBCRUPD C:DEAD WAITING ON R:LTXNLOCK 00000008 0A60730D
DC001001 TXNID:000369476 RUID:000369476 RUNAME:DBCRUPD SSC:DBCRSSC1 |
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rajasekar2810
New User
Joined: 22 Apr 2008 Posts: 6 Location: india
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Yes exactly in the IDMS logs I find this out.
Let me share my findings;
This situation happens when a record DB key is dead locked by some transaction and that record is requested by some other transactions and the TASK is getting in to loop.This leads to 0069 error.
Do you have any more idea on this. |
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dick scherrer
Moderator Emeritus
Joined: 23 Nov 2006 Posts: 19244 Location: Inside the Matrix
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Hello,
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happens when a record DB key is dead locked by some transaction |
Possibly you mean "locked" rather than "dead locked". One transacton might lock something, but not cause a deadlock.
A deadlock is typically caused when 2 different processes read 2 different tables in not the same order. Pg1 reads TbA key1 with lock. Pg2 reads TbB key2 with lock. To this point - no problem. Now, Pg2 needs to read TbA key1 with lock - it cannot because of the lock issued by PgA. It will wait until the lock is freed. What causes the deadlock is while Pg2 is waiting, PgA needs to read TbB key2 with lock. At this point the deadlock (sometimes called a "fatal embrace") is detected and the request causing the deadlock is terminted with an error.
The way to prevent this is to make sure the code locks rows in multiple tables in the same order or make sure the programs do not run concurrently. |
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