Re: opatch auto

From: Hans Forbrich <fuzzy.graybeard_at_gmail.com>
Date: Wed, 13 Feb 2013 23:32:05 -0700
Message-ID: <511C84E5.1090008_at_gmail.com>



On 13/02/2013 8:42 AM, Purav Chovatia wrote:
> Hi,
> Anybody observed, that "opatch auto" first patches the DB home and then the
> GI Home. Shouldn't it be the other way round?
>
> Thanks

As usual with Oracle: "It Depends".

Patches MAY

- impact current software;
- impact current data dictionary;
- impact dependents

Just because a GI patch is released, does not mean that it directly impacts DBs that are involved with that GI.

If a GI patch does impact DB, you probably want to patch the DB first, because you can add code to understand the new functionality as well as the code to keep compatibility. If you upgraded the GI first, it might introduce new functionality that the old DB code does not understand. Which would mean the DB must be down from before the GI is patched to after the DB is patched.

Whereas patching DB first can (in theory, depending on the extent of the GI patch impact, and whether we use RAC or only protected single node) could mean the DB is down only for the DB patch, and perhaps a quick reboot after the GI patch.

In fact, (bold statement here:) unless it impacts the interconnect (specifically the way the DB rides over the interconnect) or the disk (specifically the way the DB reads/writes ASM disks), I see limited concern about the order in which things are patched. Does that mean we can pick and choose the order when we do things manually? No - because if we happen to choose wrong in production, it is on our neck, not Oracle's.

However, if Oracle does the patch testing correctly, they can decide which combination of impacts are affected.

Also, since Oracle has KSplice technology, and since that technology can do in-place updates, I see no reason why Oracle could not do the equiv to KSplice to GI and DB, at least on certain platforms, thereby patching without ANY downtime at all. Which introduces a whole new set of possibilities (and a whole new set of problems).

In conclusion: Do it the way Oracle says. If it doesn't work, we can complain to Support. (LOL)

/Hans

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Received on Thu Feb 14 2013 - 07:32:05 CET

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