Topic 1 Question 53
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 country You 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?Users are running too many concurrent queries in the system
The [myproject:mydataset.mytable] table has too many partitions
Either the state or the city columns in the [myproject:mydataset.mytable] table have too many NULL values
Most rows in the [myproject:mydataset.mytable] table have the same value in the country column, causing data skew
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Should be D
👍 25[Removed]2020/03/21D; Purple is reading, Blue is writing. so majority is reading.
👍 22itche_scratche2020/04/18BTW, how is the query even syntactically valid? It has non aggregated columns in the SELECT part of the query. That query will not run in the first place, unless I'm missing something.
👍 14Paul_Oprea2022/05/01
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