If the package is static, then it will need to read the new statistics to
pick the best path to take.






"Park James Y. "
<db2udbdba-ezmlms
hield-x66224752.x To
[Email Address Removed] "LazyDBA Discussion"
a.com> <[Email address protected]
cc
08/28/2006 10:01
AM Subject
RE: Is reorgchk necessary










Why do you reorg, runstats and rebind? In doing maintenance we usually
did reorg and runstats not rebinding. What is the purpose of doing that?
I don't know why rebind is used.


Thanks

James

-----Original Message-----
From: Kylin
[mailto:db2udbdba-ezmlmshield-x63566171.[Email address protected]
Sent: Sunday, August 27, 2006 9:45 AM
To: LazyDBA Discussion
Subject: Is reorgchk necessary


Hi,

As my understanding, reorg will physically move records in a table
according the primary index sequence. So that durning the query, less IO
operations are needed.

reorgchk will generate a report accoding some statistic informations. It
seems there will be a threshold. When this threshold reaches, it will
mark the table or index with a * to tell reorg is necessary.

But from my point of view, doing reorg as frequently as possible is
better. When disordered records accumulate to a certain degree, it will
cost longer time to run reorg. It just likes if you sort your book once
a week or once a month.

So I think reorg should be perfrom in spite of the result of reorgchk.
If a table is ordered, "reorg" won't move any records. It works only
when a table is disordered. Besides, reorgchk itself costs time to
generate the report.

Following is my preferred Database Maintenance Process:

reorg --> runstats -> rebind

I'm also not clear about the reorg on index. Since there can be only one
primary index for one table, so the records can sort according only one
sequence. What will the reorg of index do? Sort the index itself but not
records in the table?

Please feel free to correct me if you find any issues. And any comments
will be greatly appreciated.

Best wishes,
Qin

**********************
*A climber to DBA*
**********************


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