Upgrade 4.6C to ECC 6.0 5 Tb Oracle 10g database takes too long

[Former Member]

Hi,

We´ve just run an upgrade test with a 5Tb database and takes too long so our downtime will be more than 3 days, is there any documents that can lead us to get a better downtime some way

Any help will be appreciated.

HP-UX

4.6C (4.6D ext kernel)

Oracle 10g with 5Tb of data

Thanks

[jim_ma · Accepted solution]

I think I may be qualified to answer your questions.

our database is 2TB and the technical down time is only 6 hours. Hopefully this benchmark can make your feel comfortable.

If you read some SAP presentation, the downtime is not related with the database size. so even your database is double our size, the downtime may not be doubled.

The tricks for reducing the downtime is simple. You need to have a good Basis/DBA. The first time should be painful but you need to find all the way to speed it up. Here are some common ones.

1. Search for SAP notes to see which processes could be run in parallel.

2. Watch the database to identified slow SQLs. You can add indexes to speed it up.

3. Check the stats for new tables during the upgrade. The new tables could cause some execution plan problems.

4. It is hard to say you need to archive some tables or not. As SAP says it depends. It will be difficult running archiving project with upgrade project.

The bottom line is a good Basis. Every software is peopleware.

[Former Member · Accepted solution]

Hi Jim, thanks for that info, I did found some notes about database size not being a key point during upgrade but as I saw the link I wrote before and the fact that the first test run they did (I was not here yet) took 7 days I was affraid that DB size was an issue but with your info I feel much confident now because there is someone out there that has the real life experience with a large database.

Archiving is not an option right now because the upgrade project has a dead line that won´t permit Archiving so that was discarded.

We have been looking for unused tables (already found one very large) and DBA´s here are looking for more problems at DB level so for sure that will rush things during technical downtime.

Also they did not used ICNV so that should help a lot reducing technical down time. I already had some notes about where to use parallel processes so will look if there are some more.

As I already wrote, I feel more confident with those numbers you gave me so I will award points and close this post.

Thanks a lot Jim.

[Former Member · Accepted solution]

Hi Jim,

Does 6 hours include Unicode conversion (Data export and import)?

Thanks

[hanse_atik2]

Hi Alberto,

I do not know if finished already the upgrade phase but nornaly you have to do PREPARE first which is a check for the upgrade.

Anyway, in the upgrade guide you will find two possiblilities to perfom an upgrade:

The SAP upgrade technology offers two upgrade strategies: downtime-minimized and resource-minimized.

Choose the strategy that is best suited to your SAP system and to your requirements concerning

system availability. Your decision depends on two factors:

- Maximum permitted downtime

- System resources

So if the downtime is too long for you so you have to use for example

1) the archiving. This means archiv table which you do not need or

2) you chooce the other upgrade methode: downtime-minimized. Maybe this will be better for you.

3) Other things you can do is to leave the downtime at ende. This means do all you can do before you go to downtime phase such PREPARE runs, confuguration etc...

I am doing the same: 4.6C to ECC 6.0 under oracle/win

I hope this will help.

Best regards

HanseAtik

[Former Member]

Hi Hanse,

Thanks for your suggestions, in fact this is my third upgrade to 6.0 and want to apologize for not writing this before but this is my first one with such a large database, the other upgrades I have done were with 150Gb and 210 Gb but they did not took much during the downtime. I found this info https://websmp109.sap-ag.de/upgradedb where we can see the SAP Upgrade Database and the media time for a 1300 Gb with the downtime minimized is 86 Hours! that is more than 3 days and this company is 7x24x365 and is one of the biggest enterprise in this country so more than 3 days is a big money lost, in fact the test run they did took 7 days! so you can imagine the scenario.

Right now I agree the only option is to do Archiving first but the people here told me it is not possible.

The upgrade will be done in a new server so I don´t know if exists some way to use this (Parallel server) to rush things out like doing upgrade on the new server and then move the changes from the old server to the new one, I know it sounds crazy because we are talking of two different versions but in this cases I have to look for all kind of solutions.

What do you think?

Thanks,

[Former Member]

The SAP consulting service may be able to deliver a custom solution specifically for your company. When we did our huge upgrade from 3.1I to ECC 6.0 they provided a custom version of the ICNV process (needed for the jump past 4.0B) that took full advantage of our hardware. Compared to the cost of the whole upgrade this service was quite reasonable and saved us 2 days of downtime. Might a good option to explore in your case.

thanx

Mark

[Former Member]

Can you do archive?

Regards,

Jack

[Former Member]

Hi,

We have Ixos but there is no posibility to do archive at the moment.

Thanks for your imput.