Hi,

We have several applications which access the oracle DB and issue
queries. Usually these applications are very close to the database
(over LAN). However some of them are going off-shore and will
communicate with the DB server over WAN. Are there any commercial
products that accelerate the communication with the Oracle DB?

(Of course replicating the database is an option, but I would want to
move away from it).

Thanks,
Ilan

On 21.08.2011 11:00, Ilan Shiber wrote:
Depending on access patterns Oracle's Times Ten might help:

http://www.oracle.com/us/products/da...he-066510.html

But: changing from LAN to WAN access is an architectural change. The
most appropriate solution to this would be to change application
architecture in a way to honor this fact. This typically means,
breaking up parts of your application into a client and server component
which communicate with a protocol that is adjusted to the nature of WAN
communication:

- higher latency
- lower throughput
- insecurity

You might also need to introduce local caching of data which rarely
changes. Since you have knowledge of the application data's nature, you
can come up with more efficient caching schemes than any generalized
tool (e.g. the database).

Note: I do not have in depth knowledge of Oracle NET's protocol.
Encryption for traffic is possible and it may be that it works well with
larger latency, although I doubt it.

Whether replication is an option mainly depends on DB access patterns:
if the database is updated infrequently but read accessed frequently
then replication might be an option. Otherwise you might end up with
much higher data traffic than necessary for the remote application to work.

Kind regards

robert

--
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On Sun, 21 Aug 2011 02:00:42 -0700, Ilan Shiber wrote:

The real questions are two:
1) How much data would you like to transfer over WAN?
2) How fast is the WAN?

The technology has to adjust to the physical reality. Did you do any
measurement? There are some basic measurements that you can do. On Unix/
Linux platforms there is utility called ifconfig which will provide you
with the statistics:

[mgogala@medo ~]$ ifconfig eth0
eth0 Link encap:Ethernet HWaddr 00:21:97:46:F3:86
inet addr:192.168.1.100 Bcast:192.168.1.255 Mask:255.255.255.0
inet6 addr: fe80::221:97ff:fe46:f386/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:735707 errors:0 dropped:0 overruns:0 frame:0
TX packets:668387 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:639377227 (609.7 MiB) TX bytes:176864365 (168.6 MiB)
Interrupt:43 Base address:0xc000

In the last line, there is the information about the number of bytes sent
and received. Also, there are other, more professional tool for measuring
the traffic as any network engineer worth his salt will tell you. Also,
there are many caching technologies, ranging from the database specific,
like x10 or more general, like memcached. There are also possibilities to
manipulate the WAN itself and turn on packet compression, add some
multiplexers. The applications itself will have to tuned as well. Use of
the array interface will have to be rigorously enforced and the
programming style should also be checked. The biggest problems usually
come from the attempts to enforce business rules on the application side,
instead of using triggers and procedures. In other words, your question
is a rather complex one and answering your question is a project.

--
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