Trang chủ Professional Data Engineer 80 / 343
Quay lại bộ đề
Question #80 Topic 1
You are using Google BigQuery as your data warehouse. Your users report that the following simple query is running very slowly, no matter when they run the query:SELECT country, state, city FROM [myproject:mydataset.mytable] GROUP BY countryYou check the query plan for the query and see the following output in the Read section of Stage:1: What is the most likely cause of the delay for this query?
A
Users are running too many concurrent queries in the system
B
The [myproject:mydataset.mytable] table has too many partitions
C
Either the state or the city columns in the [myproject:mydataset.mytable] table have too many NULL values
D
Most rows in the [myproject:mydataset.mytable] table have the same value in the country column, causing data skew