What is the overhead for the backup compress option ?

[Jean-Marc Blaise]

Hi,

I get a SQL2009C when using the 'compress' option for backup, but the
util_heap_sz does not blow if I do not use the 'compress' option. What is
the overhead induced by the compress option in the BACKUP command ?

Platform: DB2 UDB V8.1 Fixpack 5 / Aix 5.1.

Thanks for your help.

Jean-Marc

[Philip Nelson]

Jean-Marc Blaise wrote:

Hi,

I get a SQL2009C when using the 'compress' option for backup, but the
util_heap_sz does not blow if I do not use the 'compress' option. What is
the overhead induced by the compress option in the BACKUP command ?

Platform: DB2 UDB V8.1 Fixpack 5 / Aix 5.1.

Thanks for your help.

Jean-Marc

My experience was that we had to increase the util_heap_sz by as much as 4
times when using the compress option.

This is because the backup now holds both uncompressed and compressed images
in memory (how that equates to 4x I don't understand !!!)

However, the labs told me that this problem would be fixed in Stinger, so
I'd look into getting Fixpack 7 onto your system ASAP (you should be doing
this anyway because of a couple of remote exploits in all prior versions)

HTH

Phil Nelson
ScotDB Limited

[Jean-Marc Blaise]

Hi Philip,

Thanks for your quick answer. I have already pushed to use FP7 :-) ... for a
migration to V8 that I have been waited for 1 1/2 year ...

Best regards,

Jean-Marc

"Philip Nelson" <te*****@scotdb.com> a écrit dans le message de
news:Gm*********************@news.easynews.com...

Jean-Marc Blaise wrote:

Hi,

I get a SQL2009C when using the 'compress' option for backup, but the
util_heap_sz does not blow if I do not use the 'compress' option. What is the overhead induced by the compress option in the BACKUP command ?

Platform: DB2 UDB V8.1 Fixpack 5 / Aix 5.1.

Thanks for your help.

Jean-Marc
My experience was that we had to increase the util_heap_sz by as much as 4
times when using the compress option.

This is because the backup now holds both uncompressed and compressed

images in memory (how that equates to 4x I don't understand !!!)

However, the labs told me that this problem would be fixed in Stinger, so
I'd look into getting Fixpack 7 onto your system ASAP (you should be doing
this anyway because of a couple of remote exploits in all prior versions)

HTH

Phil Nelson
ScotDB Limited