Tim,
I believe that DB2 UDB doesn't take locks on index pages, only on the data pages. It uses a latch type process to protect the index from updates, but only while a write is in progress. This is conceptually similar to the TYPE 2 index manager on OS/390. However, due to some differences in the way that inserts are processed, UDB has an additional lock class, the NKS (next key sequential) that is used to protect RR scanners from phantom reads.
Wayne Driscoll
Sr. Software Developer
Quest Software
[EMAIL PROTECTED]
NOTE: All opinions are strictly my own.
-----Original Message-----
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]]
Sent: Monday, March 17, 2003 2:40 PM
To: [EMAIL PROTECTED]
Subject: [DB2EUG] Locking on indexes
Hello List,
When SQL is executed against a table that has one or more indexes defined against it, what type of locks, if any, are taken on the index? What type of index locking, if any, needs to be considered when SQL is executed against tables that have indexes defined on them? I looked in the Administration Guide : Performance manual at the lock mode table section and it shows the different locks that are taken based on table scans and various different index accesses. Regarding the different index accesses section, I am confused whether this is describing the locks taken on the table or locks taken on the indexes.
Any input on this would be appreciated.
Thanks,
Tim Traxson
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