MaxDB MAXDATAVOLUME - is it possible to decrease this parameter?

[Former Member]

Hi,

We have a few systems where MAXDATAVOLUME is too high:

MAXDATAVOLUME x file size is bigger than hard drive size.

We don't want to increase size of hard drive - because those databases are not growing fast and it would be waste of hundreds of gigabytes.

It is easy to increase MAXDATAVOLUME parameter - MaxDB Studio - change parameter - restart database - voila - works.

But is it possible to DECREASE?

When I have changed MAXDATAVOLUME to lower level (but still bigger than current number of active data files) and restart database - it comes back to previous (higher) value automatically.

Database version is: 7.8.02.41

MaxDB database studio version is: 7.9.09

--

Daniel

[JamesZ · Accepted solution]

Hi Daniel,

maxdb adapt MAXDATAVOLUME automatically?  This is curious.

Please attach diagpack.tgz after executing following command:

dbmcli -d <dbsid> -u <username>,<password> diag_pack


Best regards,
James

[Former Member · Accepted solution]

James,

I'm attaching diagpack (.tgz changed to .txt)

Yes parameter MaxDataVolumes  is changing automatically after system restart

20160614 00124629 MaxDataVolumes                  18                              20                                                              C GENERAL                                                                                

diagpkg.txt.zip

[simon_matter · Accepted solution]

It was my impression that MaxDataVolumes is automatically increased to "current volumes" + 10. Maybe someone who knows it better can comment on how the mechanism works exactly.

[Former Member · Accepted solution]

Simon,

I'm surprised now

Yes you are right  - I have checked many databases and MAXDATAVOLUME is equal to current volume number + 10

So - as it works automatically - how to protect system to against disk drive overflow?

And how it compares to setup of: Automatic Data Area Adjustment (ON/OFF)?

For me both does the same.

--

Daniel

[simon_matter · Accepted solution]

Hi Daniel,

MaxDataVolumes only shows the number of data volumes you can have without restarting the MaxDB instance. No data volume is added automatically.

AFAIK the "Automatic Data Area Adjustment" does the same as you can do manually, it adds data volumes. I guess it can usually add up to 10 data volumes without restarting the instance.

So both options are different but have related meanings.

Regards,

Simon