Re: star join optimization

On 14/11/11 13:09, Greg Smith wrote:
> On 11/14/2011 10:44 AM, Rudyar wrote:
>> Ok, I'm working in that project. I will send you my results
>> and comparision with SQL server HHJ optimization in one or two months.
>
> Please be careful not to share here details of how features like this 
> are built in any commercial databases you evaluate.  Some of those 
> implementations use patented design approaches that should be avoided 
> in an open source project.  Oracle, Microsoft, and DB2 are all 
> aggressive about patenting the innovative parts of their database 
> server code.
>
> In addition to not wanting to accidentally incorporate such a design, 
> it's better for the PostgreSQL project to not be aware of what patents 
> in this area exist too.  We don't even want a survey of patents in 
> this area published here because there are increased penalties for 
> willful patent infringement.  See 
> http://en.wikipedia.org/wiki/Treble_damages for example.
>
> What this project likes best are innovative approaches from recent 
> academic research that haven't been incorporated in any commercial 
> products yet.  A good example is how the Serializable Snapshot 
> Isolation technique developed by Cahill and others was added to 
> PostgreSQL 9.1:  http://wiki.postgresql.org/wiki/Serializable  There 
> was less concern over accidentally duplicating a patented approach 
> because that technique wasn't in any of the commercial databases yet.
>
Greg,

Ok. I will consider your recommendations.

Best Regards.

-- 
Rudyar Cortés.
Estudiante de Ingeniería Civil Informática
Universidad Técnica Federico Santa María.