Details on DB2_SKIPDELETED

[misterutterbag]

Hi.

We have deadlocks involving DELETEs, and I was hoping that
DB2_SKIPDELETED might be able to help in the short term.

I was looking at the following link:

"http://publib.boulder.ibm.com/infocenter/cmgmt/v8r3m0/index.jsp?topic=/com.ibm.cmgmtreadmefp.doc/d104742.htm"

It states that:

db2set DB2_EVALUNCOMMITTED=ON
db2set DB2_SKIPINSERTED=ON
db2set DB2_SKIPDELETED=ON

(specifically DB2_SKIPDELETED) are variables which can protect from
locking in some cases.

Is this intended to protect a SELECT from deadlocking against a DELETE?

And do you know which versions of DB2 have these variables available?

Any help would be much appreciated.

Joel

[Mark A]

<mi************@yahoo.comwrote in message
news:11**********************@v45g2000cwv.googlegr oups.com...

Hi.

We have deadlocks involving DELETEs, and I was hoping that
DB2_SKIPDELETED might be able to help in the short term.

I was looking at the following link:

"http://publib.boulder.ibm.com/infocenter/cmgmt/v8r3m0/index.jsp?topic=/com.ibm.cmgmtreadmefp.doc/d104742.htm"

It states that:

db2set DB2_EVALUNCOMMITTED=ON
db2set DB2_SKIPINSERTED=ON
db2set DB2_SKIPDELETED=ON

(specifically DB2_SKIPDELETED) are variables which can protect from
locking in some cases.

Is this intended to protect a SELECT from deadlocking against a DELETE?

And do you know which versions of DB2 have these variables available?

Any help would be much appreciated.

Joel

It takes two different applications, each locking on two different objects
to cause a deadlock (usually from two different SQL statements).

With DB2_SKIPDELETED=ON, if a row is deleted by application program 1, then
application program 2 will assume the row does not exist (and will not
lockwait on that row) even if application 1 has not committed the delete.

I believe DB2_SKIPDELETED=ON was introduced in 8.1 FP 4.