Questions regarding the multi-db plugin

Hi all,

I have few questions regarding the multi-db plugin which I hope someone can please help me with them:

The installation manual wrote: There is one other table you’ll need to create (2 if you intend to  provide a VIP database).  To create these tables you’ll just want to  copy one of the lines generated from the database tool and use the same  root database name with additional tags of “global”  (and vip1, vip2,  etc if needed).  So you’re final output for this line will look  something like this:

CREATE DATABASE dbname_global DEFAULT CHARACTER SET utf8 COLLATE utf8_general_ci;

1. As far as I understand VIP databases, are created for the purpose that if and only if we found a blog with a lot of traffic, then we can move this blog to the VIP database….which then could be re-allocated on a separate server….but then I saw you writing:

“A note about VIP databases:  These allow you to place a blog in a  specific database. Unless you have a blog/site that gets a ton of  traffic and you want to put it on another physical server for performance reasons, then it’s not really worth it to bother with that feature.”

So I am pretty confused about the VIP database and why shall we use them? and how can we benefit from the multi-db plugin if we found that there is a blog that have a huge traffic on it?

2. I don’t think I understood the purpose of the Global database here? So can someone please explain to me the purpose of the Global database? and…

2.A. Is it only one database or there can be more than one globlal database?

2.B. What’s the relation between this database and plugins? Actually will I need to re-setup / re-adjust any installed plugins after finishing the setup of the multi-db plugin?

3. In move-blogs.php, I don’t think I understand the main purpose of newdb_prefix field? I mean what exactly shall I enter there?

Thanks in advance for your time