Re: Multi Threaded Server (MTS)

From: Phil Herring <revdoc_at_uow.edu.au>
Date: 1998/03/11
Message-ID: <6e74ro$q5n$1@wyrm.its.uow.edu.au>#1/1

In article <01bd4b5e$f711f480$9c802192_at_banu-hou130-1.hou130.chevron.com> Full Name, cai_at_chevron.com writes:
>Can anyone tell me the advantage or dis advantage of using MTS

Without MTS, every connection to your database will create a process on your server. These processes are called "dedicated servers", and of course, they induce a load on the operating system.

In the best case (enough memory to keep all processes and data structures in RAM), since each connection has its own server process, it doesn't have to wait for database operations, and performance is optimal.

In the worst case (not enough memory), processes and data structures get swapped out, and performance is poor, as connections have to wait for things to get swapped in before accessing the database.

Under MTS, the RDBMS maintains a pool of server processes that are shared by connections. As a result, the system memory requirements are greatly reduced, but each connection has to wait for a shared server when it needs any database operations.

However, in interactive applications, the slowdown using MTS is usually imperceptible, and if you need to avoid that for some connections but not others, you can simply specify a dedicated server in your connection. It's not a matter of "either one or the other".

MTS is a tradeoff. For example, even if you currently have enough memory to use dedicated servers without swapping, you may find that the memory that it frees up can be given to more DB block buffers or sort space, resulting in a nett performance improvement. All I can suggest is that you try some tests, as every situation is different.

Received on Wed Mar 11 1998 - 00:00:00 CST