Practice Test 3 | Google Cloud Certified Professional Data Engineer | Dumps | Mock Test

Question 10

The data analytics team in your corporation is using commercial visualization software to build dashboards for management and commercial reporting. The software is integrated with the corporation’s data warehouse, which is BigQuery, to fetch the data. The finance team reported a hike in billing costs for Google Cloud since the visualization software is being used. You were asked to find the root cause of this. You found that the BigQuery bill was relatively higher compared to previous months due to querying. You checked that caching is enabled so this should not be due to the queries written by data analysts and used for visualization.

Which of the following are valid reasons for BigQuery not using cached queries? (Choose 2 Options)

A. Queries select from the authorized views on archive tables.
B. Queries use nested fields.
C. Queries use now() function.
D. Queries multiple tables using wildcard table.

Answer

Correct Answer: C and D

In BigQuery, cached results are not supported for queries against multiple tables using a wildcard even if the “Use Cached Results” option is checked. If you run the same wildcard query multiple times, you are billed for each query.

If the query uses non-deterministic functions; for example, date and time functions such as CURRENT_TIMESTAMP() and NOW(), and other functions such as CURRENT_USER() return different values depending on when a query is executed

For the complete list of query cases not cached in BigQuery, check “BigQuery – Using Cached Query Results” below.

Source(s):

BigQuery – Using Cached Query Results: https://cloud.google.com/bigquery/docs/cached-results

BigQuery – Wildcards:

https://cloud.google.com/bigquery/docs/querying-wildcard-tables

BigQuery – Cached Results:

https://cloud.google.com/bigquery/docs/cached-results