Re: ramfs or ram disk
Date: Wed, 21 Aug 2013 22:54:17 +0100
Message-ID: <CAOCOAV+AbAd7tC6X=iKqkON4baufgjwdsT_SUBnqPggOqmzxwQ_at_mail.gmail.com>
I accept that using a ram disk would be relatively safe for a temporary tablespace.
However I remember when Oracle absolutely forbade the use of sparse files. Then at some point Oracle has started using sparse files for temporary tablespaces and I have seen no new official position on sparse files.
I would be cautious about putting a sparse temporary tablespace on a ramdisk.
A reccomendation I should have included in my original response is: open an SR to verify that your new proposed configuration is fully supported.
I will however restate my original position, if your ram is fully commited, then creating a ramdisk will rob another part of your system of a valuable resource.
For example if most of your temporary tablespace usage is for sorting, reducing the sort area size to make space for a ramdisk will not solve your performance problem as you will simply increase the number of sorts that spill to disk.
If developers have made extensive use of global temporary tables inappropriatley then you may be able to inprove performance using a ramdisk.
However I would still contend that fixing the real problem with the code rather than using the sticking plaster of a ramdisk.
There are valid uses of ramdisks but they are rare and sometimes do not constitute a long term solution.
Dave
-- http://www.freelists.org/webpage/oracle-lReceived on Wed Aug 21 2013 - 23:54:17 CEST