2.4 Optimize Database Cost and Performance in Google Cloud PROFESSIONAL-CLOUD-DATABASE-ENGINEER Practice Questions (Page 1)

Questions 1–5

1. 1application · medium

   A company runs a Cloud Spanner instance for its global inventory system. The workload is steady, but the team wants to ensure they are not over-provisioning and paying for unused capacity. They have been monitoring the instance and see that CPU utilization is consistently below 20%. What should they do?

   • AReduce the number of nodes in the instance.
   • BSwitch to a multi-region configuration to improve availability.
   • CEnable autoscaling on the instance.
   • DIncrease the number of nodes to improve performance.
   Reveal Solution Discussion Select an answer first
2. 2expert · medium

   A company runs a Cloud SQL for PostgreSQL instance for its order management system. The database has a table with 100 million rows. A query that filters on a non-indexed column `status` is slow. The team adds an index on `status`, but the query is still slow. What is the most likely reason?

   • AThe query is selecting a large percentage of the rows in the table.
   • BThe instance does not have enough memory to cache the index.
   • CThe index is not being used because the column has a high number of NULL values.
   • DThe index was created with the `CONCURRENTLY` option.
   Reveal Solution Discussion Select an answer first
4. 3application · medium

   A company runs a development and a production environment for its application, both using Cloud SQL for PostgreSQL. The development environment is used only during business hours, while production runs 24/7. The team wants to reduce costs without affecting production performance. What should they do?

   • AEnable automatic storage increases on both instances.
   • BDowngrade the production instance to a smaller machine type.
   • CMove the development environment to Cloud Spanner.
   • DStop the development instance outside business hours.
   Reveal Solution Discussion Select an answer first
5. 4expert · medium

   A company runs a Cloud Spanner instance for its global e-commerce platform. The instance is a multi-region configuration. The team is experiencing high write latency during peak hours. They have identified that the issue is due to a hotspot on a single key. What is the most effective way to resolve this?

   • AUse a secondary index to improve write performance.
   • BAdd a random suffix to the primary key to distribute writes.
   • CSwitch to a single-region configuration to reduce write latency.
   • DIncrease the number of nodes in the instance.
   Reveal Solution Discussion Select an answer first
6. 5application · medium

   A company uses BigQuery for its sales analytics. A dashboard query filters on `order_date` and `product_id`. The table is partitioned by `order_date` and clustered by `product_id`. The team notices that the query is still scanning a large amount of data. What is the most likely cause?

   • AThe table is not partitioned by `order_date`.
   • BThe `product_id` column is not included in the SELECT statement.
   • CThe query is using a function on the `order_date` column in the WHERE clause.
   • DThe clustering is not working because the table is too small.
   Reveal Solution Discussion Select an answer first