Re: Tablesspaces and Datafiles - Max Sizes?

James Hanway wrote:
>
> Hi All,
>
> I'm looking at building a rather large database to hold ocean mapping
> data, currently in v7.3.4, soon to be in v8.0.5 on a Digital UNIX box.
> The idea is to keep a LARGE chunk of data from an even larger "off-line"
> archive sitting on-line in a series of tables within a massive
> tablespace. Sizes of close to 300-500 GIG on-line have been tossed
> around.
>
> To date, I've never pushed the size of individual datafiles past 1000M,
> which of course means 300-500 individual datafiles for that tablespace.
> Anyone have any comments/thoughts on how large a datafile can *SAFELY*
> be, and how many datafiles a given tablespace can have, and its
> relationship to the MAXDATAFILE clause of the CREATE DATABASE command?
>
> Cheers!
>
> James

A few comments. I don't know Digital UNIX, but on HP/UX you have a choice of 32 bit or 64 bit versions of the operating system and there's a 64 bit version of Oracle. This can make a difference. Secondly, we have a ROT that says any multi table tablespace over 6 GB should be split into multiple tablespaces. This simplifies backup and recovery. Why do you want all these archive tables in one tablespace? Lastly, I recommend installing at least v8.0.6 as v8.0.5 will be out of support at the end of the year.

One system I have has about 500 datafiles with no problem. We have datafiles of just under 2GB each with a total of 930GB and growing. We have MAXDATAFILES set to 1022 as a carryover from the maximum for Oracle7. The MAXDATAFILES parameter can be set to the maximum for your operating system. If it's too small trying to create a datafile once you have reached the max will fail. To change this parameter you need to recreate your control files. Note that the larger the MAXDATAFILES parm is, the larger the control files will be. Also, the more datafiles you have the more work Oracle needs to do at each checkpoint to keep the SCN numbers in sync.

Big Al Received on Wed Sep 13 2000 - 14:23:51 CDT