DB2 UDB AIX environment variable db2_rr_to_rs

Paul Ealey

DB2 UDB AIX environment variable db2_rr_to_rs
I have been advised to switch the environment variable db2_rr_to_rs = YES in
order to reduce or eliminate deadlocks between transactions in testing.

The manual says that "if request to access a user table using Repeatable
Read (RR) is received the request is modified internally to use the Read
Stability (RS) instead."

Our packages do not use RR, however, I'm assured that it will have an effect
anyway.

Can anyone in either the user or IBM community comment please.

Paul Ealey
EDS, UK



Wayne Driscoll

Re: DB2 UDB AIX environment variable db2_rr_to_rs
(in response to Paul Ealey)
Paul,
It's been a while, but I believe that setting db2_rr_to_rs will allow UDB to
no longer take NEXT KEY (NS, NW, or NX) locks during insert or delete
operations. This can improve performance in applications that do a lot of
insert/delete operations, regardless of the isolation level.
Wayne Driscoll
Product Developer
Quest Software Inc.
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Note: All opinions are strictly my own.

-----Original Message-----
From: Ealey, Paul M [mailto:[login to unmask email]
Sent: Wednesday, December 11, 2002 6:40 AM
To: [login to unmask email]
Subject: [DB2-L] DB2 UDB AIX environment variable db2_rr_to_rs


I have been advised to switch the environment variable db2_rr_to_rs = YES in
order to reduce or eliminate deadlocks between transactions in testing.

The manual says that "if request to access a user table using Repeatable
Read (RR) is received the request is modified internally to use the Read
Stability (RS) instead."

Our packages do not use RR, however, I'm assured that it will have an effect
anyway.

Can anyone in either the user or IBM community comment please.

Paul Ealey
EDS, UK