Db2

Hi all,

I'm currently investigating the usage of DEDUP_DEVICE Keyword in Db2 BACKUP command. I know there used to be a Whitepaper written by @Dale McInnis covering Db2 Backups DEDUP feature - it was available in Developerworks and was called dm-1302db2deduplication. Unfortunately I do not have a copy in my
private archive and do not find the paper here in the library nor anywhere else in the web

Anybody has a copy of it  and can upload it here?

TIA
Joachim
Db2Joe

Hi all,

I'm currently investigating the usage of DEDUP_DEVICE Keyword in Db2 BACKUP command. I know there used to be a Whitepaper written by @Dale McInnis covering Db2 Backups DEDUP feature - it was available in Developerworks and was called dm-1302db2deduplication. Unfortunately I do not have a copy in my
private archive and do not find the paper here in the library nor anywhere else in the web

Anybody has a copy of it  and can upload it here?

TIA
Joachim
Db2Joe

Hi Joachim,

I also tried my Google skills and used the wayback machine. But the wayback machine has only recorded http 300 errors. So my assumption is, that the link to this document is not correct.
My next attempt would be to contact Dale directly, if he still has a copy around. And, yes, I see he has already replied.

Dedup is an interesting idea, which can easily compress file system backups  of client machines in TSM aka Spectrum Protect (at the moment), as they have many repeating patterns. I don't see much repeating patterns in database pages in a single database. Even without encryption or compression I assume the entropy of your data should be high enough to prevent duplicate pages.

It could be different for backing up many copies of the same database. However, then deduplication is probably blind to a single BACKUP command. Only in the backend, dedup can be resolved before saving to tape.

Just my €0.03 on the topic. And yes, I would also like to have a copy of the whitepaper. Just in case someone else is looking for this someday.

Cheers
Roland

P.S. Right after writing the above sentences, I re-read your OP again and I remember Dale saying, DEDUP_DEVICE is just a keyword to run a backup in a slightly different pattern to support external deduplication. But this also has implications to read from a stream. I have to think about this on my flight to IDUG NA next week...

Hi all,

I'm currently investigating the usage of DEDUP_DEVICE Keyword in Db2 BACKUP command. I know there used to be a Whitepaper written by @Dale McInnis covering Db2 Backups DEDUP feature - it was available in Developerworks and was called dm-1302db2deduplication. Unfortunately I do not have a copy in my
private archive and do not find the paper here in the library nor anywhere else in the web

Anybody has a copy of it  and can upload it here?

TIA
Joachim
Db2Joe

Here is the paper I published from 2013.

Hi Joachim,

I also tried my Google skills and used the wayback machine. But the wayback machine has only recorded http 300 errors. So my assumption is, that the link to this document is not correct.
My next attempt would be to contact Dale directly, if he still has a copy around. And, yes, I see he has already replied.

Dedup is an interesting idea, which can easily compress file system backups  of client machines in TSM aka Spectrum Protect (at the moment), as they have many repeating patterns. I don't see much repeating patterns in database pages in a single database. Even without encryption or compression I assume the entropy of your data should be high enough to prevent duplicate pages.

It could be different for backing up many copies of the same database. However, then deduplication is probably blind to a single BACKUP command. Only in the backend, dedup can be resolved before saving to tape.

Just my €0.03 on the topic. And yes, I would also like to have a copy of the whitepaper. Just in case someone else is looking for this someday.

Cheers
Roland

P.S. Right after writing the above sentences, I re-read your OP again and I remember Dale saying, DEDUP_DEVICE is just a keyword to run a backup in a slightly different pattern to support external deduplication. But this also has implications to read from a stream. I have to think about this on my flight to IDUG NA next week...

Hi all,

I'm currently investigating the usage of DEDUP_DEVICE Keyword in Db2 BACKUP command. I know there used to be a Whitepaper written by @Dale McInnis covering Db2 Backups DEDUP feature - it was available in Developerworks and was called dm-1302db2deduplication. Unfortunately I do not have a copy in my
private archive and do not find the paper here in the library nor anywhere else in the web

Anybody has a copy of it  and can upload it here?

TIA
Joachim
Db2Joe

Hi Joachim,

I also tried my Google skills and used the wayback machine. But the wayback machine has only recorded http 300 errors. So my assumption is, that the link to this document is not correct.
My next attempt would be to contact Dale directly, if he still has a copy around. And, yes, I see he has already replied.

Dedup is an interesting idea, which can easily compress file system backups  of client machines in TSM aka Spectrum Protect (at the moment), as they have many repeating patterns. I don't see much repeating patterns in database pages in a single database. Even without encryption or compression I assume the entropy of your data should be high enough to prevent duplicate pages.

It could be different for backing up many copies of the same database. However, then deduplication is probably blind to a single BACKUP command. Only in the backend, dedup can be resolved before saving to tape.

Just my €0.03 on the topic. And yes, I would also like to have a copy of the whitepaper. Just in case someone else is looking for this someday.

Cheers
Roland

P.S. Right after writing the above sentences, I re-read your OP again and I remember Dale saying, DEDUP_DEVICE is just a keyword to run a backup in a slightly different pattern to support external deduplication. But this also has implications to read from a stream. I have to think about this on my flight to IDUG NA next week...

Hi all,

I'm currently investigating the usage of DEDUP_DEVICE Keyword in Db2 BACKUP command. I know there used to be a Whitepaper written by @Dale McInnis covering Db2 Backups DEDUP feature - it was available in Developerworks and was called dm-1302db2deduplication. Unfortunately I do not have a copy in my
private archive and do not find the paper here in the library nor anywhere else in the web

Anybody has a copy of it  and can upload it here?

TIA
Joachim
Db2Joe