I think that the "maximum number of records in a group" of 18032 is
really hurting the file performance.  I would find that group, and see
what keys are being hashed to it.  How many other groups approach this
number of records?  How bad are the other partfiles in this regard?

Something about your keys is causing a lot of them to hash to one group
or a selected subset of groups.

Also, how many groups out there have absolutely no records in them?
You've got 3,000,000 groups but only 2,000,000 records - so you should
have something in the neighborhood of 1,000,000 empty groups.  If you
have 2,500,000 empties - then your key values are not hashing well under
type 18.

-----Original Message-----
From: [EMAIL PROTECTED]
[mailto:[EMAIL PROTECTED] On Behalf Of roy
Sent: Wednesday, October 17, 2007 9:52 AM
To: [email protected]
Subject: [U2] Size of key question

  _____  

From: Roy Beard [mailto:[EMAIL PROTECTED]
Sent: Tuesday, October 16, 2007 10:33 PM
To: '[email protected]'
Subject: File key question

 

Wow!

 

I got so many ideas from this group that I thought I would give some
more Information.

 

This file is a distributed file in 2 parts The 3rd field (separated by
*) determines which partfile with "1" going to the file I sent before
and the rest going to this file

 

There are no triggers on the file.

 

The system was 'fast' until recently when tens of thousands of new
records were added.  I agree the file is poorly sized, it was an attempt
to solve one problem but created another.

 

The keys, I believe, are an issue

 

Here is a sample

&SUMMARY&*PRO*1*&SUMMARY&*CDJ*9876***WS

407*BAR*1*498*GLU*2274***&SUMMARY&

491*BAR*1*498*GLU*2274***&SUMMARY&

&SUMMARY&*BAR*1*498*GLU*2274***&SUMMARY&

1896*BAR*1*498*GLU*2274***&SUMMARY&

460*BAR*1*498*GLU*2274***&SUMMARY&

1199*&SUMMARY&*1*465*432*9999***

1185*&SUMMARY&*1*412*ABE*&SUMMARY&***BLIN

3281*&SUMMARY&*1*412*ABE*&SUMMARY&***BLIN

&SUMMARY&*&SUMMARY&*1*412*ABE*&SUMMARY&***BLIN

&SUMMARY&*&SUMMARY&*1*450*HIR*&SUMMARY&***AMEL

3558*&SUMMARY&*1*450*HIR*&SUMMARY&***AMEL

3811*&SUMMARY&*1*450*HIR*&SUMMARY&***AMER

&SUMMARY&*&SUMMARY&*1*450*HIR*&SUMMARY&***AMER

3558*&SUMMARY&*1*450*HIR*&SUMMARY&***AMER

&SUMMARY&*CAG*1*429*LOR*1810***BURN

252*PON*1*640*SHE*FRT***

2177*CS1*1*491*ABE*&SUMMARY&***

590*PRO*1*491*JOR*&SUMMARY&***WW8RHH

3715*PRO*1*491*JOR*&SUMMARY&***WW8RHH

Press any key to continue...

 

Here is the file stat from the other half of the file  File name =
SALES-HIST-BRS

File type                               = 18

Number of groups in file (modulo)       = 3000017

Separation                              = 1

Number of records                       = 2071678

Number of physical bytes                = 1894588928

Number of data bytes                    = 356514112

 

Average number of records per group     = 0.6906

Average number of bytes per group       = 118.8374

Minimum number of records in a group    = 0

Maximum number of records in a group    = 18032

 

Average number of bytes per record      = 172.0895

Minimum number of bytes in a record     = 64

Maximum number of bytes in a record     = 2704

 

Average number of fields per record     = 25.7575

Minimum number of fields per record     = 11

Maximum number of fields per record     = 41

 

Groups   25%     50%     75%    100%    125%    150%    175%    200%
full

     2789365   44352   31348   23325   33111    9221    9893   59402

Press any key to continue...

 

 

I'll be working on this for a while.  Any resize, copy etc. has such an
impact on the system that my access is limited.

 

Thanks for the input so far.

 

Roy

 

 

 

 

 

 

Roy C. Beard

Distributor Solutions Inc

P.O. Box 110520

Palm Bay, FL 32911-0520

 

321-956-6500

501-642-8698   Fax
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