Course Management

1. Count of records for the 2024 Yellow Taxi Data (1 point)

65,623

840,402

20,332,093

85,431,289

2. Estimated amount of data (1 point)

18.82 MB for the External Table and 47.60 MB for the Materialized Table

0 MB for the External Table and 155.12 MB for the Materialized Table

2.14 GB for the External Table and 0MB for the Materialized Table

0 MB for the External Table and 0MB for the Materialized Table

3. Why are the estimated number of Bytes different? (1 point)

BigQuery is a columnar database, and it only scans the specific columns requested in the query. Querying two columns (PULocationID, DOLocationID) requires reading more data than querying one column (PULocationID), leading to a higher estimated number of bytes processed.

BigQuery duplicates data across multiple storage partitions, so selecting two columns instead of one requires scanning the table twice, doubling the estimated bytes processed.

BigQuery automatically caches the first queried column, so adding a second column increases processing time but does not affect the estimated bytes scanned.

When selecting multiple columns, BigQuery performs an implicit join operation between them, increasing the estimated bytes processed

4. How many records have a fare_amount of 0? (1 point)

128,210

546,578

20,188,016

8,333

5. The best strategy to make an optimized table in Big Query (1 point)

Partition by tpep_dropoff_datetime and Cluster on VendorID

Cluster on by tpep_dropoff_datetime and Cluster on VendorID

Cluster on tpep_dropoff_datetime Partition by VendorID

Partition by tpep_dropoff_datetime and Partition by VendorID

6. Estimated processed bytes (1 point)

12.47 MB for non-partitioned table and 326.42 MB for the partitioned table

310.24 MB for non-partitioned table and 26.84 MB for the partitioned table

5.87 MB for non-partitioned table and 0 MB for the partitioned table

310.31 MB for non-partitioned table and 285.64 MB for the partitioned table

7. Where is the data for external tables stored? (1 point)

Big Query

Container Registry

GCP Bucket

Big Table

8. Always clustering (1 point)

True

False

Homework 3: Data Warehousing

Correct answers