Re: 9/18 Visual Planner Meeting Wrapup
Perhaps I'm missing the point of the question, since I wasn't able to
attend, but I'll give it a shot:
Show me all faculty members (table Faculty) that have the same last
name as a student (table Student).
There would, of course, be no reason to have an FK between those
columns, implicit or explicit. I imagine that a number of
data-mining-type queries that are trying to discover new information
or correlations within a database might have this characteristic.
Miss you guys (and the food up here actually kinda sucks),
James
Quoting "Mark Wong" <markwkm(at)gmail(dot)com>:
While Selena and Gabrielle were dining with the other speakers at the
Linux Plumbers Conference, this month's PDXPUG meeting featured Tom
Raney and his Google Summer of Code project at Portland State
University under the mentoring of Dr. Len Shapiro. Before getting
into the details of the Visual Planner, Tom gave a great high level
overview of PostgreSQL's decision making process for determining how
to execute a SQL statement. Then he gave brief description of changes
in the PostgreSQL code that are required in order for the Visual
Planner to capture all the plans that the database considered
executing. Using the tool, Tom demonstrated how to browse through all
the discarded plans to see the cost estimates of each plan indicating
why those plans were discarded. Hopefully people who will be attended
the PostgreSQL West Conference 2008 in October will have a chance to
see Tom repeat his performance.
Len also posed an interesting question that I will try to repeat accurately:
Can anyone come up with an example of a meaningful query where there
is a join that does not use an implicit or explicit foreign key?
There were a couple of new comers and we hope to see them again.
After the meeting some of us headed to the Lucky Lab for refreshments!
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