Exercise 61

1
Exercise 6-1

• Given a video database of old sports broadcasts,
  called SportsVidLib, express the following users
  information needs using the extended SQL as best
  as possible. You should comment on how well the
  extended SQL is able to capture each users
  information need and discuss alternative ways of
  expressing the information need more fully.
• Bob wants to see all the video sequences with
  Michael Owen kicking a ball
• Tom wants to see all the video sequences in which
  Vinnie Jones is tackling Paul Gascoigne
• Mary wants to see all the video sequences in
  which Roy Keane is arguing with the referee,
  because Jose Reyes punched Gary Neville, while
  Thierry Henry scores a goal, and then Roy Keane
  is sent off.

2
Bob wants to see all the video sequences with
Michael Owen kicking a ball
SELECT vid s,e FROM video
SportsVidLib WHERE (vid,s,e) IN
FindVideoWithObjects(Michael Owen) AND (vid,s,e)
IN FindVideoWithObjects(ball) AND (vid,s,e) IN
FindVideoWithActivityandProp(Kick, Kicker,
Michael Owen) AND (vid,s,e) IN
FindVideoWithActivityandProp(Kick, Thing_Kicked,
Ball) This captures the user information need
precisely (unless you consider that it does not
explicitly state that it is the same instance of
a Kick activity). It may be inefficient to
have to include the FindVideoWithObjects lines.
3
Tom wants to see all the video sequences in which
Vinnie Jones is tackling Paul Gascoigne

• SELECT vid s,e
• FROM video SportsVidLib
• WHERE
• (vid,s,e) IN FindVideoWithObjects(Vinnie Jones)
  AND
• (vid,s,e) IN FindVideoWithObjects(Paul Gascoigne)
  AND
• (vid,s,e) IN FindVideoWithActivityandProp(Tackle,
  Tackler, Vinny Jones) AND
• (vid,s,e) IN FindVideoWithActivityandProp(Tackle,
  Person_Tackled, Paul Gascoigne)
• Similar comments as previous example.

4
Mary wants to see all the video sequences in
which Roy Keane is arguing with the referee,
because Jose Reyes punched Gary Neville, while
Thierry Henry scores a goal, and then Roy Keane
is sent off.

• In this case it is possible to describe the
  objects and activities (like in previous
  examples), but it is not possible to make
  explicit the temporal and causal relationships
  between the activities with the VideoSQL
  formalism.

5
Think about

• What metadata would be required in order to
  execute these kinds of video query?
• How could this be stored and searched most
  efficiently?