Re: Using symbolic links for data files ??

From: Jgreene <jgreene_at_aol.com>
Date: 24 Dec 1994 11:04:57 -0500
Message-ID: <3dhgr9$ecd_at_newsbf02.news.aol.com>


In article <1994Dec19.152251.487_at_cho006>, Chris Little <little_c_at_cho006.cho.ge.com> wrote:
>Running Oracle 7.0.16 on HP-UX 9.04
>
>By default, the oracle installer places data files in the
>$ORACLE_BASE/data/SID directory, but the Installation Guide
>implies that data files should be distributed across multiple
>devices and that the directory $ORACLE_BASE/data/SID should
>be empty.
>
>My intention is create symbolic links in this directory which
>point to data files distributed across multiple disks. This way,
>if I need to move a file, I can take the tablespace offline,
>move the file, modify the link, and bring the tablespace back
>online again, without having to ALTER TABLESPACE RENAME DATAFILE...
>
>This approach would also seem beneficial for backup and recovery
>because all symbolic links for a database are in a single directory.
>
>Has anybody out there done this, or does anybody see a problem with
>this? I would be grateful for any helpful comments and advice.
>
I have worked on a 13 GB Oracle database that uses this for almost all of its files. With the exception of a few tablespaces like system, tools, etc., most of the data was located on mirrored raw partitions. A link directory was created that contained nothing but the symbolic links to the raw device files. We chose the names of the links so that they identified what the tablespace was (i.e. it had sa in the title for sales or di for dimensions, along with an identifier to show whether it contained tables or indexes and a sequential number since we had many disks associated with a tablespace). It worked well. It was easy when a disk was lost to restore the data to an alternate disk and then merely modify the link. Since many of the error messages that identified problems with data files list the data file name (and number, but who remembers the numbers), it helped to be able to identify what data was affected by reading the name of the link. Good luck. Received on Sat Dec 24 1994 - 17:04:57 CET

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