Re: Using OPTIMIZER_CAPTURE_SQL_PLAN_BASELINES=TRUE in Production
From: LKaing Gmail <lkaing_at_gmail.com>
Date: Fri, 10 May 2019 19:17:46 +1000
Message-Id: <E1905705-BAED-4845-939A-BC1568CAE4ED_at_gmail.com>
> Yes. And?
>
> Your database must be very small if the control file auto-backup makes such a difference. Control file size is expressed in MB, usually less than 100 MB. With database sizes regularly reaching tens of TB, 50 MB is not such a big deal. Disks are getting rather big these days:
>
>
> https://www.extremetech.com/extreme/233358-seagate-unveils-the-worlds-largest-ssd-60tb
>
> https://www.pcworld.com/article/3256281/samsung-30tb-ssd-pm1643.html
>
> You can buy 4TB SSD on Amazon:
>
> https://www.amazon.com/Samsung-Inch-Internal-MZ-76E4T0B-AM/dp/B07864XY8B/ref=sr_1_fkmr2_2
>
> Rotational drives with capacity of 6TB or 8TB are dime a dozen. These days typical redo log size for a large database exceeds 1GB, which is about 20 times larger than the typical control file. I really don't see a problem with having a control file auto-backup being a part of every backup I create. This reminds me of the good old times when some storage was only having 1.2 MB or 1.4 MB of space for the entire piece of hardware. That was called "floppy", and was something that many people working today have never seen used. That was before CD's and DVD's which are very much obsolete today, just as floppy drives are.
>
>
>
> --
> Mladen Gogala
> Database Consultant
> Tel: (347) 321-1217
>
> --
> http://www.freelists.org/webpage/oracle-l
>
>
Date: Fri, 10 May 2019 19:17:46 +1000
Message-Id: <E1905705-BAED-4845-939A-BC1568CAE4ED_at_gmail.com>
Well if controlfile_file_record_keep_time is 352 and maxloghist is huge, and you’re taking rman archiving backups every 10 minutes...
Anyway, all I’m saying is that sometimes the recommended setting may not necessarily be turned on by default. Force logging is also another favourite of mine. I’d like it on by default too.
As for this particular parameter I still haven’t turned it on system wide either.
> On 10 May 2019, at 5:13 pm, Mladen Gogala <gogala.mladen_at_gmail.com> wrote:
>
>
>> On 5/9/19 9:32 PM, Leng Burgess wrote: >> eg. If you backup archive logs every 10 minutes, you’d get a control file auto backup every 10 minutes too! On one environment
> Yes. And?
>> I saw that the backupset for control file auto backups were much larger than any other backup sets!!
>
> Your database must be very small if the control file auto-backup makes such a difference. Control file size is expressed in MB, usually less than 100 MB. With database sizes regularly reaching tens of TB, 50 MB is not such a big deal. Disks are getting rather big these days:
>
>
> https://www.extremetech.com/extreme/233358-seagate-unveils-the-worlds-largest-ssd-60tb
>
> https://www.pcworld.com/article/3256281/samsung-30tb-ssd-pm1643.html
>
> You can buy 4TB SSD on Amazon:
>
> https://www.amazon.com/Samsung-Inch-Internal-MZ-76E4T0B-AM/dp/B07864XY8B/ref=sr_1_fkmr2_2
>
> Rotational drives with capacity of 6TB or 8TB are dime a dozen. These days typical redo log size for a large database exceeds 1GB, which is about 20 times larger than the typical control file. I really don't see a problem with having a control file auto-backup being a part of every backup I create. This reminds me of the good old times when some storage was only having 1.2 MB or 1.4 MB of space for the entire piece of hardware. That was called "floppy", and was something that many people working today have never seen used. That was before CD's and DVD's which are very much obsolete today, just as floppy drives are.
>
>
>
> --
> Mladen Gogala
> Database Consultant
> Tel: (347) 321-1217
>
> --
> http://www.freelists.org/webpage/oracle-l
>
>
-- http://www.freelists.org/webpage/oracle-lReceived on Fri May 10 2019 - 11:17:46 CEST