Question Re: MaxDB MAXDATAVOLUME - is it possible to decrease this parameter? in Technology Q&A

MaxDB MAXDATAVOLUME - is it possible to decrease this parameter?

Former Member — Wed, 15 Jun 2016 11:38:32 GMT

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

Re: MaxDB MAXDATAVOLUME - is it possible to decrease this parameter?

JamesZ — Fri, 17 Jun 2016 08:15:06 GMT

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

Re: MaxDB MAXDATAVOLUME - is it possible to decrease this parameter?

Former Member — Fri, 17 Jun 2016 10:34:40 GMT

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

Re: MaxDB MAXDATAVOLUME - is it possible to decrease this parameter?

simon_matter — Sat, 18 Jun 2016 10:21:12 GMT

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.

Re: MaxDB MAXDATAVOLUME - is it possible to decrease this parameter?

Former Member — Mon, 20 Jun 2016 11:07:32 GMT

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

Re: MaxDB MAXDATAVOLUME - is it possible to decrease this parameter?

simon_matter — Mon, 20 Jun 2016 13:08:30 GMT

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