Re: In-memory database

From: Dave Hau <davehau-no-spam-123_at_no-spam.netscape.net>
Date: Sun, 09 Nov 2003 21:29:45 GMT
Message-ID: <dlyrb.3381$pJ.2861_at_newssvr23.news.prodigy.com>


And if your application only does reads and not writes on the database, then you just need to set the buffer cache in Oracle to large enough to hold all your data, and the undo tablespaces. Then you do a couple of select statements that'll cause a full table scan of each table and a fast full index scan of each index. There you have all your data in memory.

  • Dave

"Dave Hau" <davehau-no-spam-123_at_no-spam.netscape.net> wrote in message news:Qbyrb.3379$6L.1485_at_newssvr23.news.prodigy.com...
> In fact, if you want fast performance, you would want to copy your redo
log
> files onto tmpfs, more so than having the data files on tmpfs, because the
> redo log files are written to synchronously when you commit, whereas the
> data files are written to asynchronously in the background (and most of
the
> data will be cached in the buffer cache anyways.) Of course, this way you
> risk losing your data if the machine crashes and tmpfs goes away. But
from
> your description, the data is for testing only and it doesn't seem this is
> an issue for you.
>
> HTH,
> Dave
>
>
>
> "Dave Hau" <davehau-no-spam-123_at_no-spam.netscape.net> wrote in message
> news:90yrb.3377$JE.2473_at_newssvr23.news.prodigy.com...
> > The linux 2.4 kernel supports tmpfs which is similar to a ramdisk. So
one
> > way you can do it is to create a mount point on tmpfs. Then go into
> Oracle,
> > create a tablespace with the datafile residing on the tmpfs mount point.
> > Now you can use that tablespace to store your schema and your data will
be
> > persisted in memory. When you're done, before shutting down Oracle,
> either
> > delete the tablespace, or copy the datafile onto your hard disk (and
copy
> it
> > back to tmpfs if you want, the next time before you start up Oracle.)
> >
> > HTH,
> > Dave
> >
> >
> >
> >
> > "Hans Schwaebli" <hans.schwaebli_at_schwaebli.de> wrote in message
> > news:boktul$bk3$04$1_at_news.t-online.com...
> > > Does Oracle support in-memory database?
> > >
> > > I want to speed up my JUnit tests which access the database. In this
> > context
> > > it is sufficient if the JUnit-Tests work with data which is persisted
in
> > > memory, not on harddisk.
> > >
> > > Any solutions?
> > >
> > >
> >
> >
>
>
Received on Sun Nov 09 2003 - 22:29:45 CET

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