Altering Memory allocation for Databases 1

[TalentedFool]

Hi all

not quite sure of what I need to do here. Basically sombody has created a database on one of our servers and left a whole load of documentation as to how he created it.

In it, he specified that he allocated 80% of the memory to the database instead of a fixed amount.

How do I go about changing that? Can I just alter the pfile memory values and stop/restart the instance?

Cheers

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[KenCunningham]

What OS is this? Isn't 80% a 'fixed amount' anyway? Sorry, I'm a little confused.

 

[TalentedFool]

Hi Ken

Its under a Solaris environment.

And yes you are quite right in that 80% is a fixed amount but my plan is to load another database on the machine but with the first database already taking so much resource I can't get the second databse up without taking away some resouce from the first and giving it to the second.

Make sense now?

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[KenCunningham]

Yes, thanks. Differing OS require different tweaking (or none at all). In Solaris, the necessary details or set in /etc/system as far as I know. For one of our systems with 4Gb memory, the /etc/system settings are as follows:

set shmsys:shminfo_shmmax=4294967295
set shmsys:shminfo_shmmin=1
set shmsys:shminfo_shmmni=100
set shmsys:shminfo_shmseg=10
set semsys:seminfo_semmns=2000
set semsys:seminfo_semmsl=1000
set semsys:seminfo_semmni=100
set semsys:seminfo_semopm=100
set semsys:seminfo_semvmx=32767

Note that this is a machine with four databases using the same Oracle siftware and the above kernel setup appears to serve them all adequately. Hope this helps.

 

[TalentedFool]

Ken

We've got those set and they are correct.

The parameters I'm talking about are things like the SGA Large pool size etc which can be set against each individual database.

Does that make sense?

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[KenCunningham]

Right, yes. All you should need to do is amend the entries in your init<SID>.ora and stop and restart the database for them to become active.

 

[TalentedFool]

Thanks Ken

Do you have any ideas about the SGA though? I've been reading that it shouldn't be more than 50% of the total amount?

How do I set the SGA?

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[KenCunningham]

Hello again. It's really a function of several init<SID>.ora settings. See:

http://asktom.oracle.com/pls/ask/f?p=4950:8:::::F4950_P8_DISPLAYID:348417553934

for a much better explanation than I could ever give you. Hope this helps a bit further.

 

[TalentedFool]

Ken

Thanks for that. Funnily enough I've just been reading a few docs from AskTom. First time I've seent hat site and it looks pretty helpfull.

Onec again - thanks for the help! Star awarded



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[KenCunningham]

Many thanks. You'll probably find that site very useful in a number of ways, but TT tends to be more useful if it's a quick answer you want, so don't be a stranger!

 

[TalentedFool]

No worries Ken - I've been on TT for some years now and do find it extremely usefull

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