[Opensim-dev] Proposal to change user ID types in prims table to support external user profiles.

[Frisby, Adam]

CHAR->VARCHAR shouldn't change too many performance properties. 

It may mean you lose fixed row size, but I doubt we didn't have any non-variable fields in the table anyway.

I suggest VARCHAR(255) for URI-storing fields.

+1 on changing to internet-unique addresses. (uuid at userhost?)

Adam

> -----Original Message-----
> From: opensim-dev-bounces at lists.berlios.de [mailto:opensim-dev-
> bounces at lists.berlios.de] On Behalf Of Justin Clark-Casey
> Sent: Wednesday, 1 April 2009 12:17 PM
> To: opensim-dev at lists.berlios.de
> Subject: [Opensim-dev] Proposal to change user ID types in prims table
> to support external user profiles.
> 
> Previously in Heroes, we discussed the propogation of profile
> information via references to a URI rather than via
> copying and persisting profiles between OpenSim systems.
> 
> As a first step towards this goal, I want to change the user ID types
> in the prims table (OwnerID, CreatorID,
> LastOwnerID) to a type that can store a reasonably long URL.  At this
> point it's only crucial to change CreatorID, but
> it seems sensible to change the other IDs at the same time since I
> believe that these will also need to store URIs
> eventually.  I don't anticipate changing the field names.
> 
> At the moment in MySQL these types are char(36).  I propose to change
> them to varchar.  However, I don't know what the
> performance penalty of this is.  If this is high than I'm open to the
> suggestion of simply having a longer char limit.
> If the performance penalty is low then I think that a varchar would be
> better.  Analogous changes would be made to
> SQLite and MSSQL (not necessarily by me).
> 
> I anticipate that no other tables need to change.  The existing UUID
> based creator/owner/lastowner functionality will
> continue to work exactly as before.
> 
> If possible I will probably make the changes next week.
> 
> I actually plan an initial implementation which preserves creator names
> only for IARs which does not use an external
> URI.  Even when a URI based system arises this can still act as a
> fallback.  I believe that a name only implementation
> can be done without copying over any profile data.
> 
> An external URI solution will come later.  On reflection, there are
> lots of difficulties and problems with an external
> URI approach but on balance I think that it's a better long term route
> than profile copying.  I anticipate further
> discussion on this nearer the time.
> 
> Comments?
> 
> --
> justincc
> Justin Clark-Casey
> http://justincc.wordpress.com
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