Re: Indexes in memory not on disk
Date: Tue, 31 Jan 1995 10:20:30 -0800
Message-ID: <Pine.SUN.3.91.950131101626.5819C-100000_at_seatimes>
On Sun, 29 Jan 1995, tim london wrote:
> > Having performance problems, we are trying to find a solution to keep the
> > indexes in memory only. We would like to avoid disk i/o for the indexes.
>
> There is no way of telling Oracle to lock an index into memory.
>
> I would suspect that you have insufficient main memory for your application.
> Try increasing DB_BLOCK_BUFFERS, but don't induce O/S paging or
> swapping.
On some hardware platforms you can obtain software to function similar to the RAM DISK in the PC world. I know that the MPE operating system has a 3rd party vendor that will supply both the extra memory and software subsystem to keep a FILE in memory.
In that case, you would need to move the INDEX to it's own TABLESPACE and have the underlying file for that tablespace kept in memory by the RAM DISC software.
However, this is working around ORACLE and doesn't really cause ORACLE to keep the index in memory. You would probably find better performance just giving the extra memory to ORACLE and letting it keep the Most Recently Used buffers in memory.
--Steve
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