Re: Demo: Things in Hierarchies (w/o RM/SQL)

a few years ago, oag for all commercial flights segments in the world had a little over 4000 airports (with commercial scheduled flights) and about half million "flight segments" (i.e. take/off landings). the number of flights segments didn't exactly correspond to flights/day ... since some flight segments didn't fly every day. there was also an issue that each individual flight segment was a flight ... plus combinations of flight segments were also flights (i.e. say flight from west coast to east coast with two stops could represent 3+2+1 different "flights"). the longest such flight that i found had 15 flight segments (it wasn't in the US) ... taking off first thing in the morning and eventually arriving back at the same airport that night ... after making the round of a lot of intervening airports.

there is also some practice of the same flight segment having multiple different flight numbers. the first instance of this (that i know of) was in the very early 70s ... the first twa flight out of sjc in the morning ... flew both to seatac and kennedy. it turns out that the people going to kennedy had a change of equipment at sfo (not a connection).

this is an airline "gimick" ... traditionally the non-stops and directs are listed before the flights with connections. if you had a dual flight number ... with change of equipment ... tho flights would show up in the first "direct" section ... not in the following "connections" section.

-- 
Anne & Lynn Wheeler | http://www.garlic.com/~lynn/