Re: Oracle Data Warehousing, UNIX and large file-enabled file systems

In article <1017091312.24426.0.nnrp-07.9e984b29_at_news.demon.co.uk>, "Jonathan says...
>
>
>I won't comment on how, or whether you platform
>can support files larger than 2GB, but as far as
>the number of files is concerned, the issue of checkpoints
>may be irrelevant. If your data has a strong time-element,
>then you may able able to work with time-based tablespaces,
>and then switch tablespaces older than a few weeks to
>readonly mode - at which point they are no longer
>subject to checkpoints and require no further backups.
>
>

Much as I hate to disagree with anything Jonathan says (it always comes back and bite me 'coz he's right!), there is one point I would like to make on this. Think about the situation where you have a read-only tablespace that was made read-only a year ago, and backed up at that stage. Can you imagine the administrative nightmare of having to go back through that many tapes to find the damn backup? In theory, Jonathan is correct. In practice, I like to back up my read-only tablespaces every so often for the reason just given. Of course, if we all had tape silos that could keep thousands of tapes ...
>--
>Jonathan Lewis
>http://www.jlcomp.demon.co.uk
>
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>Author of:
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>
>
>Don Gillespie wrote in message
><6ffd83a6.0203251137.50307a5f_at_posting.google.com>...
>>I am the DBA for a data warehouse environment that is expected to get
>>to about 3TB. That would mean about 1500 or so data files with the
>>2GB file limit. Besides being a nightmare to manage that many files,
>>I anticipate the overhead on checkpoints would be tremendous. The
>>environment is 32-bit Oracle (possibility of 64 bit in the future) on
>>AIX with disk storage on an IBM Shark SAN (RAID5, 32K stripe; no
>>choice here), with a 16K Oracle block size (the max allowed). We are
>>using Journaled File Systems, not raw partitions. I am contemplating
>>the use of large file-enabled JFSs for all JFSs that would contain
>>oracle data files, log files and control files. But I don't know much
>>about them, and I am wondering if there are serious performance, space
>>consumption or administration issues in doing so.
>>
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>
>

HTH. Additions and corrections welcome.

Pete

SELECT standard_disclaimer, witty_remark FROM company_requirements; Received on Mon Mar 25 2002 - 17:49:40 CST