This simplified E$/$R schema shows a Travel Company specializing in Bus Trips.

Passengers buy tickets for trips, with each trip having a bus, driver, starting and ending location.

The time dimension consists of day, month and year.

Trips have a travel distance between the starting and ending city.

Please identify the fact of interest and build the attribute tree. Prune any attributes $($if necessary$)$ that are not of interest.

Attributes that cannot be used for aggregation in a meaningful way should be tagged as non$-$dimension attributes in the fact schema.

Then derive the fact schema from the tree by defining dimensions, fact attributes and hierarchies and build a glossary for the fact attributes if there are any.

$1.$ Identify fact of interest, dimensions, and measures.

$2.$ For each fact:

a$.$ Produce the attribute tree

b$.$ Produce the fact schema.

c$.$ Design the star, galaxy, snowflake, or star cluster schema that fits.