Archive - Originally posted on "The Horse's Mouth" - 2006-04-06 18:36:12 - Graham Ellis
"Can we have more helicopter views?" asked a client from whom we're running a series of courses - by which they mean overviews that put all the elements of the technologies in place on a diagram - showing how tomcat relates to MySQL and how JBoss and Struts and EJBs fit in to the picture. For sure you can, and I note the term "Helicopter views" to add to my dictionary of metaphors.
"Do you have any Scots in the group?" I ask my class, as I use another Metaphor to explain how MySQL's select command restricts the returned values to just a tiny subset of the data available. If you have a tartan where 20% of the warp threads are green, and where 20% of the weft threads are green, then your cloth has only 4% of its area being full green - green on green. Translate that into a Select command; if you choose just a fifth of the columns in a table, and you then use a where clause where just 20% of the rows are selected, your result set, efficiently, is just 4% of the data held.
"Can we have more helicopter views?" asked a client from whom we're running a series of courses - by which they mean overviews that put all the elements of the technologies in place on a diagram - showing how tomcat relates to MySQL and how JBoss and Struts and EJBs fit in to the picture. For sure you can, and I note the term "Helicopter views" to add to my dictionary of metaphors.