During certain times of the day, DB2 will have lock escalations on one of its tables. This happens about once or twice a day in the AM. I would assume this is due to heavy activity. How do I stop the lock escalations? I think there is a lock percentage parameter that can be changed.
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DB2 Lock Escalations
- Thread starter tooquic
- Start date
gregsimpson
Programmer
- Apr 18, 2002
- 521
tooquic,
MAXLOCKS defines a percentage of the lock list held by an application that must be filled before the database manager performs lock escalation. The range is from 1 to 100 percent.
LOCKLIST indicates the amount of storage allocated to the locklist. There is one lock list per database and it contains all the locks held by all applications concurrently connected to the database.I believe the range for this is 4 -60,000 in terms of 4k pages.
Cheers
Greg
MAXLOCKS defines a percentage of the lock list held by an application that must be filled before the database manager performs lock escalation. The range is from 1 to 100 percent.
LOCKLIST indicates the amount of storage allocated to the locklist. There is one lock list per database and it contains all the locks held by all applications concurrently connected to the database.I believe the range for this is 4 -60,000 in terms of 4k pages.
Cheers
Greg
Increase the LOCKLIST parameter. Note that the lock will consume memory based on the type of installation.
If you have 32 bit installation, then it consumes
36 bytes to lock an object that has a lock on it.
72 bytes to lock an object that doesnot has a lock on it.
If you have 64 bit installation, then it consumes
56 bytes to lock an object that has a lock on it.
112 bytes to lock an object that doesnot has a lock on it.
Based on this you increase the LOCKLIST parameter.
On a trial, you can increase it to 1.5 times of current value. Then if you don't see any lock-escalation, try to decrease it and this will make room to increase the bufferpools.
Hope this helps.
Goodluck.
ifmxtechie.
If you have 32 bit installation, then it consumes
36 bytes to lock an object that has a lock on it.
72 bytes to lock an object that doesnot has a lock on it.
If you have 64 bit installation, then it consumes
56 bytes to lock an object that has a lock on it.
112 bytes to lock an object that doesnot has a lock on it.
Based on this you increase the LOCKLIST parameter.
On a trial, you can increase it to 1.5 times of current value. Then if you don't see any lock-escalation, try to decrease it and this will make room to increase the bufferpools.
Hope this helps.
Goodluck.
ifmxtechie.
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