RE: Characterset change

From: Tiwari, Yogesh <"Tiwari,>
Date: Thu, 17 Jan 2019 04:34:09 +0000
Message-ID: <16B7E76F772C9141A2BCA83CD8D9250162840341_at_INDEL7005WIN.intl.intlroot.fid-intl.com>

Upendra,

I'd suggest go to 19c(12.2.0.3) instead, which is a terminal release. It is due in May of this year under GA. This also means vendor apps need certification on 19c too. There are significant changes in performance as you move up from 12.1(Oracle brought in changes, and then rolled them back later).

I, normally as a quick way, assess a database version by checking certification of database version used by OMS repository. I just take this as a clue to understand what must be used with caution. For e.g. 13c OMS repository notes on underlying database (12.1) clearly stated parameters they don't use. Although, published those to the world as game-changer.

Anyway, in my opinion, here's how I ll plan...

1. Do linux upgrade(preferably to 7.6) plus characterset change, and keep db at 12.1 and patch it to latest PSU as well.
   • I don't think you ll see many performance issues, but your apps need to do rigorous functional testing.
   • App teams mostly cut corners on infrequent jobs, like monthly, quarterly or adhoc user jobs.
2. Later, do database upgrade to 19c.

Thanks,
Yogi
Disclaimer: The information transmitted is intended for the person or entity to which it is addressed and may contain confidential, privileged or copyrighted material or attorney work product. If you receive this in error, please contact the sender and delete the material from any system. Any unauthorised copying, disclosure or distribution of the material in this e-mail is strictly forbidden. Any comments or statements made are not necessarily those of Fidelity. All e-mails may be monitored or recorded.

From: Upendra nerilla [mailto:nupendra_at_hotmail.com] Sent: 17 January 2019 09:28
To: Tiwari, Yogesh <Yogesh.Tiwari_at_fidelity.co.in>; Oracle-L <oracle-l_at_freelists.org> Subject: Re: Characterset change

Thanks for the feedback. Great points.
I have been looking into the Pros and Cons of 12.2 upgrade + Characterset conversion in a single maintenance window vs splitting them as well. This is a business critical database, a bunch of apps running.. Hence I am leaning towards performing the 12.2 upgrade (stabilize things) and then go through a character-set conversion. Would love to hear any feedback on this approach as well.

I am also trying to fit the Linux upgrade with the character-set since it would be almost a rebuild..

-Upendra

---

From: Tiwari, Yogesh <Yogesh.Tiwari_at_fidelity.co.in<mailto:Yogesh.Tiwari_at_fidelity.co.in>> Sent: Wednesday, January 16, 2019 10:20 PM To: nupendra_at_hotmail.com<mailto:nupendra_at_hotmail.com>; Oracle-L Cc: Tiwari, Yogesh
Subject: RE: Characterset change

Upendra,

On a side note. Since you are are on RHEL 6.7, which is due for EOL and so is 12.1 by year-end. You might want to club this migration within same downtime(unless, ofcourse you want to create a physical standby(mounted) which doesn't need extra license other than EE. Don't open it in read-only).

In my experience, you might want to work with application team around lossy data that has no means of conversion. Most of the times vendor applications built on such code pages don't readily change, and you end up continuing the same.

• DBMA ll let you validate changes, and you can put of it in an excel(report) and compute storage requirements. You may want to add some buffer as well.
• Datapump ll not handle lossy data.
• TTS can't be used for characterset change.

Thanks,

Yogi

Disclaimer: The information transmitted is intended for the person or entity to which it is addressed and may contain confidential, privileged or copyrighted material or attorney work product. If you receive this in error, please contact the sender and delete the material from any system. Any unauthorised copying, disclosure or distribution of the material in this e-mail is strictly forbidden. Any comments or statements made are not necessarily those of Fidelity. All e-mails may be monitored or recorded.

From: oracle-l-bounce_at_freelists.org<mailto:oracle-l-bounce_at_freelists.org> [mailto:oracle-l-bounce_at_freelists.org] On Behalf Of Upendra nerilla Sent: 17 January 2019 01:42
To: Oracle-L <oracle-l_at_freelists.org<mailto:oracle-l_at_freelists.org>> Subject: Characterset change

Hello Oracle Experts -

Environment: Redhat 6.7, EE 12.1

DB size: 4TB

We have been looking into switching the Characterset of a DB from "WE8ISO8859P15" to "AL16UTF8".

This is a standalone Enterprise Edition database (non-RAC, No Data Guard).

We have looked at DB Migration Assistant and DataPump as possible options. Both involves quite a bit of downtime,

wondering if there is a better way to perform this activity? Would Transportable tablespace be an option?

Thanks much in advance

-Upendra

--
http://www.freelists.org/webpage/oracle-l

Received on Thu Jan 17 2019 - 05:34:09 CET