Db2 zOS SYSCOLDIST Type N rows

Michael Hannan

Db2 zOS SYSCOLDIST Type N rows

Does anyone know exactly what circumstances cause Type 'N' rows to be stored in SYSCOLDIST over type 'F' rows. I can read the documentation of course and see it says Non-padded rows, which would seem to apply to VARCHAR columns since Type 'F' normally pad VARCHAR values out to maximum length of the VARCHAR. I don't recall seeing any Type 'N' rows so am guessing there are special circumstances. Not as simple as having a VARCHAR in the Frequent Value.

Query on a major subsytem to find Type 'N' rows found nothing. Used in multi-column (COLGROUP) freq value Stats with VARCHAR? Or some other situation? Very long VARCHAR (which normally would not be indexed) but could be collected by manually specifying?

Michael Hannan,
DB2 Application Performance Specialist
CPT Global Ltd

 

Edited By:
Michael Hannan[Organization Members] @ Dec 13, 2018 - 07:30 AM (Europe/Berlin)
Michael Hannan[Organization Members] @ Dec 13, 2018 - 07:35 AM (Europe/Berlin)

Roy Boxwell

Db2 zOS SYSCOLDIST Type N rows
(in response to Michael Hannan)
I see them in the SYSKEYTARGETS and never in SYSCOLDIST



SELECT STATS_FORMAT, COUNT(*)

FROM SYSIBM.SYSKEYTARGETS

GROUP BY STATS_FORMAT

;

---------+---------+---------+---------+-

STATS_FORMAT

---------+---------+---------+---------+-

93

N 65

DSNE610I NUMBER OF ROWS DISPLAYED IS 2



Not exactly what you were asking for...



Roy Boxwell

SOFTWARE ENGINEERING GmbH and SEGUS Inc.
-Product Development-

Heinrichstrasse 83-85
40239 Duesseldorf/Germany
Tel. +49 (0)211 96149-675
Fax +49 (0)211 96149-32
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Web http://www.seg.de http://www.seg.de

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Software Engineering GmbH
Amtsgericht Düsseldorf, HRB 37894
Geschäftsführung: Gerhard Schubert, Ulf Heinrich



From: Michael Hannan [mailto:[login to unmask email]
Sent: Thursday, December 13, 2018 7:29 AM
To: [login to unmask email]
Subject: [DB2-L] - Db2 zOS SYSCOLDIST Type N rows



Does anyone exactly what circumstances cause Type 'N' rows to be stored in SYSCOLDIST. I can read the documentation of course and see it says Non-padded rows, which would seem to apply to VARCHAR columns since Type 'F' normally pad VARCHAR values out to maximum length of the VARCHAR. I don't recall seeing any Type 'N' rows so am guessing there are special circumstances. Not as simple as having a VARCHAR in the Frequent Value.

Michael Hannan,
DB2 Application Performance Specialist
CPT Global Ltd





-----End Original Message-----

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Walter Jani&#223;en

AW: Db2 zOS SYSCOLDIST Type N rows
(in response to Michael Hannan)
Hi Michael

I don’t see any TYPE ‘N’ in our system in SYSCOLDIST

Kind regards
Walter Janißen [standard_IBM+Champ+7+Yr+Analytics]

ITERGO Informationstechnologie GmbH
Anwendungsentwicklung
Technische Anwendungsarchitektur
Victoriaplatz 2
D-40198 Düsseldorf
[login to unmask email]<mailto:[login to unmask email]>

ITERGO Informationstechnologie GmbH
Vorsitzender des Aufsichtsrats: Christian Diedrich
Geschäftsführung: Dr. Bettina Anders (Vorsitzende),
Lothar Engelke, Ina Kirchhof, Dr. Michael Regauer
Sitz: Düsseldorf, Handelsregister: Amtsgericht Düsseldorf HRB 37996

Von: Michael Hannan <[login to unmask email]>
Gesendet: Donnerstag, 13. Dezember 2018 07:29
An: [login to unmask email]
Betreff: [DB2-L] - Db2 zOS SYSCOLDIST Type N rows


Does anyone exactly what circumstances cause Type 'N' rows to be stored in SYSCOLDIST. I can read the documentation of course and see it says Non-padded rows, which would seem to apply to VARCHAR columns since Type 'F' normally pad VARCHAR values out to maximum length of the VARCHAR. I don't recall seeing any Type 'N' rows so am guessing there are special circumstances. Not as simple as having a VARCHAR in the Frequent Value.

Michael Hannan,
DB2 Application Performance Specialist
CPT Global Ltd



-----End Original Message-----
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Michael Hannan

RE: Db2 zOS SYSCOLDIST Type N rows
(in response to Roy Boxwell)



In Reply to Roy Boxwell:

I see them in the SYSKEYTARGETS and never in SYSCOLDIST



SELECT STATS_FORMAT, COUNT(*)

FROM SYSIBM.SYSKEYTARGETS

GROUP BY STATS_FORMAT

;

---------+---------+---------+---------+-

STATS_FORMAT

---------+---------+---------+---------+-

93

N 65

DSNE610I NUMBER OF ROWS DISPLAYED IS 2



Not exactly what you were asking for...



Roy Boxwell

SOFTWARE ENGINEERING GmbH and SEGUS Inc.
-Product Development-

Heinrichstrasse 83-85
40239 Duesseldorf/Germany
Tel. +49 (0)211 96149-675
Fax +49 (0)211 96149-32
Email: <mailto:[login to unmask email]> [login to unmask email]
Web http://www.seg.de http://www.seg.de

https://www.seg.de/corporate/rechtliche-hinweise/datenschutz Link zur Datenschutzerklärung


Software Engineering GmbH
Amtsgericht Düsseldorf, HRB 37894
Geschäftsführung: Gerhard Schubert, Ulf Heinrich

Thanks heaps, Useful information. Sometimes we did not know how best to frame the question, so the answer may well need a reinterpretation.

 

Michael Hannan,
DB2 Application Performance Specialist
CPT Global Ltd

Michael Hannan

RE: AW: Db2 zOS SYSCOLDIST Type N rows
(in response to Walter Janißen)



In Reply to Walter Janißen:

Hi Michael

I don’t see any TYPE ‘N’ in our system in SYSCOLDIST

Kind regards
Walter Janißen [standard_IBM+Champ+7+Yr+Analytics]

I think we need to look for the 'N' type Dist rows in SYSKEYTGTDIST based on Roy's post, where SYSKEYTARGETS  indicates N format. So for Index on Expression or XML Indexes. Many sites may not have any XML Indexes.

Michael Hannan,
DB2 Application Performance Specialist
CPT Global Ltd