Does anybody have a production database that is 100% in RAM? I am
considering putting a 1 Tb Informix 11.5 (or 11.7) database in AIX
RAM. I know that backup and logging will probably have to go to disk
and I will have to restore every time the machine goes down. But with
compressed backups, that might not be too bad. Anyway, if anyone has
done this, what issues have you had to deal with? What tuning
surprises came up?

Thanks,
L.S.

On 13/09/2011 21:00, LIGHT SCANS wrote:
I'm pretty sure they played with this at lastminute.com on Solaris, but
after my time there.

It would have been 10.x not 11

There may or may not be other people here who know more...

--
Clive

Is this an OLTP server or Data Warehouse/Decision Support?

If it is the latter, or a combo server, take a serious look at the new
Informix Warehouse Accellerator. I keeps a compressed copy of tables you
are interested in querying with complex DW style queries (as many tables as
needed and as much data as memory will hold with 50-70% compression) and it
processes complex queries 100-1500 times as fast as the basic Informix
engine can for any complex queries or even simple queries that return
significant numbers of rows with filtering. Even using RAM disk, Informix
cannot reach that level or performance on its own!

If this is for a pure OLTP environment take a look at the Solid DB Cache for
Informix. It accelerates OLTP transactions by moving the active portions of
your tables into memory data structures optimized for in-memory access.

Both solutions work seamlessly with your existing Informix instance and you
submit queries to Informix just as you do now, but qualifying queries are
forwarded to the IWA or Solid engine for processing. The Solid DB Cache for
Informix can also use its own interface, either way it has access to both
its own in-memory copy of the data and other data residing in the underlying
Informix engine.

Art

Art S. Kagel
Advanced DataTools (www.advancedatatools.com)
Blog: http://informix-myview.blogspot.com/

Disclaimer: Please keep in mind that my own opinions are my own opinions and
do not reflect on my employer, Advanced DataTools, the IIUG, nor any other
organization with which I am associated either explicitly, implicitly, or by
inference. Neither do those opinions reflect those of other individuals
affiliated with any entity with which I am affiliated nor those of the
entities themselves.



On Tue, Sep 13, 2011 at 4:00 PM, LIGHT SCANS <light_scans (AT) yahoo (DOT) com> wrote:

It is an OLAP data warehouse that our vice presidents want to add new
OLTP requirements to (with near zero wait time). We looked into
compression but Informix can only do that on a table by table basis.
And we have a just few tables where that would apply (the largest is
60 Gb). Therefore my rough estimate is that compression would only
save us about 150 Gb (because if I unloaded all my data without
indexes I would have a 300 Gb file). The Accelerator, based on a
quick review, seems to be a RAM copy on a separate server of our
choosing. This adds complexity and other issues like network speed.
I assume Art is right because I have learned a lot from him (and
others in this newgroup) for many years. But since the OLTP queries
are simple, the main issue I see with "my" single, local, home-grown
RAM system is that the OLAP queries will force OLTP queries to wait
(even on RAM!). I guess the Accelerator would act as a copy that we
could just let the OLTP queries run on. But we are lucky that we
could make our OLAP queries run at night and OLTP during the day.

Actually, it would be the other way around. You would reformat the database
for OLTP and let the Warehouse Accelerator handle the OLAP queries in
memory.

The Warehouse Accelerator can run on the same machine as the server IFF the
server is running on Intel Linux (IWA only runs on Linux x86/64) and has
enough memory to make it worth your while. Otherwise it can run on a
separate Linux machine (regardless of the platform on which the server is
running). Believe me, the speed increases for your OLAP queries would more
than make up for any network faster than 300baud (tee hee - but you get the
point)!

If you need to go the other way, OLAP from disk and OLTP from memory, then
you need the Solid DB Cache for Informix, which I also described, instead.

Art

Art S. Kagel
Advanced DataTools (www.advancedatatools.com)
Blog: http://informix-myview.blogspot.com/

Disclaimer: Please keep in mind that my own opinions are my own opinions and
do not reflect on my employer, Advanced DataTools, the IIUG, nor any other
organization with which I am associated either explicitly, implicitly, or by
inference. Neither do those opinions reflect those of other individuals
affiliated with any entity with which I am affiliated nor those of the
entities themselves.



On Tue, Sep 13, 2011 at 6:30 PM, LIGHT SCANS <light_scans (AT) yahoo (DOT) com> wrote:

Great advice. I will look more deeply into the options you suggest.

Thanks!
L.S.