[Opensim-dev] Proposal to eliminate the name, description and invType fields from the assets db table

[Justin Clark-Casey]

This is mainly a question for core developers, though other viewpoints 
are welcomed.

In the OpenSim assets database table currently there are eight fields

+-------------+-------------+------+-----+---------+-------+
| Field       | Type        | Null | Key | Default | Extra |
+-------------+-------------+------+-----+---------+-------+
| name        | varchar(64) | NO   |     |         |       |
| description | varchar(64) | NO   |     |         |       |
| assetType   | tinyint(4)  | NO   |     |         |       |
| invType     | tinyint(4)  | NO   |     |         |       |
| local       | tinyint(1)  | NO   |     |         |       |
| temporary   | tinyint(1)  | NO   |     |         |       |
| data        | longblob    | NO   |     |         |       |
| id          | varchar(36) | NO   | PRI |         |       |
+-------------+-------------+------+-----+---------+-------+

Of these, name, description and invType are not really used by OpenSim 
(there are a couple of places in the code that use invType, but these 
could easily use other data sources).  Name and description are a little 
pointless for assets - the real names and descriptions are actually 
always kept in the inventory items which reference these assets. 
InvType is also information which is always duplicated in items.

Eliminating these fields would have the following advantages

1.  Make it easier to save and load and integrate assets with locations 
outside OpenSim.  If you don't need to maintain name, description or 
invType, it should be possible to save assets with the uuid embedded in 
the filename and an extension which shows the asset type (e.g. .jp2 for 
JPEG2000 textures).  The assets wouldn't require persistence of the 
local and temporary attributes.

Two immediate use cases are that elimination of these asset fields would 
  make the creation and manipulation of archives and inventory libraries 
much simpler.  There may also be integration benefits.  For instance, 
asset data files could be served directly by a stock webserver without 
having to wrap them in XML to provide the extra metadata).  Moreover, if 
we adopt generation of UUIDs using a hashing algorithm (e.g. SHA1) at 
some stage, we wouldn't even need to embed the UUID in the name.

2.  Eliminate the code which maintains these fields, simplifying the 
codebase and making it easier to read.  This is a minor point, since the 
amount of code isn't large.

3.  Reduce data storage requirements.  This is also a minor point, since 
these fields will always be dwarfed by the blobs (although this might 
come into play much further down the line if blobs are moved out of the db).

The one disadvantage I can think of is

1.  It becomes a little hard to get a sense of what's in your asset 
database by just browsing the assets table.  For instance, you get a 
rough sense of how many objects are in prim or avatar inventories by 
counting the number of times that 'Primitive' appears as a name... 
However, statistical information could still be derived (if desired) by 
analysing the type field.

In summary, I would like to see if the name, description and invType 
asset table fields can be removed at some point in the near future. 
Does anybody have a good or necessary reason to retain them?

-- 
justincc
Justin Clark-Casey
http://justincc.wordpress.com