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.
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