[Opensim-users] Database overview needed

[Frank W Sweet]

Impalah wrote: The connection between them is 
assetID(inventoryItems)->id(assets) but there aren't any foreign keys.

The asset UUID in the inventory record is a foreign key. Located in 
one table (inventoryitems), it is the unique key to an entry in a 
different table (assets). The problem, in this specific example, is 
that if the asset record is copied whenever it is modified, for fear 
that some other inventory item might be pointing to it, eventually 
most of the asset records in my database will be junk--not referenced 
by any item and so unreachable. Worse yet, due to glitches and 
crashes, an inventory item might be pointing to a non-existent 
asset-ID. (Now that I know the data structure, I have already found 
several such situations in my database.)

Frank W Sweet
Backintyme Publishing.

----- Original Message ----- 
From: "Impalah" <impalah at gmail.com>
To: "Frank W Sweet" <fwsweet at backintyme.com>; 
<opensim-users at lists.berlios.de>
Sent: Tuesday, March 03, 2009 9:12 AM
Subject: Re: [Opensim-users] Database overview needed


Not, there aren't any, at least in the "original" opensim servers.

Asset server is a huge store of anything, even the generated maps and
terrain revisions (opensim region servers). Not only inventory assets 
are
stored there.

Asset server and inventory server are separated processes each one 
with
their own data models. The connection between them is
assetID(inventoryItems)->id(assets) but there aren't any foreign keys. 
You
could use different databases for assets/inventory.

I have only doubts about the new AssetsInventory server, I hadn't time 
to
play with it.

Greetings

2009/3/3 Frank W Sweet <fwsweet at backintyme.com>

> Thank you so much! I had no idea that section of the Wiki was out
> there!
>
> One other question: Since there is no reference counter in "asset" 
> for
> inventory-to-asset references (nor in "userfriend" for
> user-to-userfriend references, nor in any other table receiving
> one-to-many relationships, for that matter), I assume that there are
> utility procedures in the code that are run periodically to purge
> unreferenced records and to check referential integrity. Where in 
> the
> code would these be, and how often are they run (at startup, 
> shutdown,
> every so often)?
>
> Frank W Sweeet
> Backintyme Publishing
>
> ----- Original Message -----
> From: "Jeff Ames" <jeffames at gmail.com>
> To: "Frank W Sweet" <fwsweet at backintyme.com>;
> <opensim-users at lists.berlios.de>
> Sent: Monday, March 02, 2009 10:58 PM
> Subject: Re: [Opensim-users] Database overview needed
>
>
> There is some existing documentation at
> http://opensimulator.org/wiki/Database:Documentation and the pages
> linked there.
>
> As for assets versus inventory items, an asset is the object itself,
> whereas the inventory item simply points to the asset (via the asset
> ID), and adds some information about the asset that the inventory
> needs to be aware of, such as permissions.
>
> When assets are modified, a copy is created, since we can't be sure
> that there is only one reference to the original asset.
>
> (I believe this is accurate, but those of you more familiar with
> current asset handling, please correct me if I'm mistaken.)
>
> Jeff
>
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