Table: f1_1990_rounds
Columns: round
grand_prix
date
location
pole_position
fastest_lap
winning_driver
winning_constructor
report

Question: What is the number of pole position with a round of 15?
SQL: SELECT COUNT("pole_position") FROM f1_1990_rounds WHERE "round" = 15

Question: What is the date of the circuit gilles villeneuve?
SQL: SELECT "date" FROM f1_1990_rounds WHERE "location" = 'Circuit Gilles Villeneuve'

Question: What is the location of thierry boutsen?
SQL: SELECT "location" FROM f1_1990_rounds WHERE "fastest_lap" = 'Thierry Boutsen'