PCDE Practice Test 10 — 10 Questions

Question 1

A gaming company uses Firestore in Native mode to store player profiles and game state. They need to query the data by both 'playerId' and 'lastLoginTimestamp' sorted descending. The current index configuration is automatic. How should they configure indexing to support this query efficiently?

Choose an answer to begin — your selection is scored in the full session.

Accepted Answer

Create a composite index on 'playerId' ascending and 'lastLoginTimestamp' descending. Firestore requires a composite index for queries that filter on one field and order by another (or filter on multiple fields). Since the query filters by 'playerId' and sorts by 'lastLoginTimestamp' descending, a composite index on 'playerId' ascending and 'lastLoginTimestamp' descending is needed. Automatic single-field indexes cannot serve this combined query, so the composite index must be created explicitly.

Answer

Create two separate single-field indexes: one on 'playerId' and one on 'lastLoginTimestamp'

Answer

Use an exemption to remove automatic indexing on 'playerId' and rely on single-field indexes

Answer

Use the automatic index configuration; Firestore will create the necessary composite index automatically

Question 2

A team needs to monitor CPU utilization on Cloud SQL databases and receive an alert when it exceeds 80% for more than 5 minutes. Which Google Cloud service should they use?

Accepted Answer

Cloud Monitoring. Cloud Monitoring (formerly Stackdriver Monitoring) is the correct service because it provides built-in metrics for Cloud SQL, including CPU utilization, and allows you to create alerting policies based on threshold conditions (e.g., CPU > 80% for 5 minutes). It integrates directly with Cloud SQL and can trigger notifications via email, Pub/Sub, or other channels when the condition is met.

Answer

Cloud Audit Logs

Answer

Active Assist

Answer

Cloud Logging

Question 3

A production Cloud SQL for PostgreSQL instance needs to handle increased read traffic and provide automatic failover in case of a zone outage. Which architecture satisfies both requirements?

Accepted Answer

Enable high availability (regional) and create a read replica in the same region.. Enabling high availability (regional) for Cloud SQL for PostgreSQL creates a primary and standby instance in different zones within the same region, providing automatic failover during a zone outage. Adding a read replica in the same region offloads read traffic from the primary instance, satisfying the increased read traffic requirement while the HA configuration ensures high availability.

Answer

Enable high availability only.

Answer

Use a CMEK key and enable binary logging.

Answer

Create multiple read replicas without HA.

Question 4

A company is migrating an on-premises PostgreSQL database to Cloud SQL. The database is 2 TB and has a high write workload. They need minimal downtime. Which migration approach is best?

Accepted Answer

Use Database Migration Service with continuous replication. Database Migration Service (DMS) with continuous replication is the best approach because it supports minimal-downtime migrations from on-premises PostgreSQL to Cloud SQL. DMS uses change data capture (CDC) to replicate ongoing writes while the initial data load completes, then performs a cutover with only seconds of downtime. This handles the 2 TB size and high write workload without requiring manual export/import or schema changes.

Answer

Use Cloud Spanner

Answer

Use Cloud SQL for MySQL instead

Answer

Export using pg_dump and import via psql

Question 5

A company is using Cloud Spanner and wants to perform disaster recovery testing. They need to validate that their backup and restore process works without impacting production. Which TWO actions should they take? (Choose 2 correct answers.)

Accepted Answer

Restore a backup to a new database in the same instance using a different database ID. Option A is correct because Cloud Spanner backups can be restored to a new database within the same instance by specifying a different database ID, which lets the team validate the restore process without touching the production database. Option D is correct because restoring a backup to a new Spanner instance in a separate test project provides full isolation from production, allowing disaster recovery testing with no impact on live workloads. Option B is not appropriate because exporting to Cloud Storage and importing is a data movement method, not the native Cloud Spanner backup/restore validation path, and it does not test the backup restore process itself. Option C is incorrect because read replica failover tests availability and replication behavior, not backup and restore. Option E is incorrect because restoring directly to the production database would overwrite or disrupt production data, violating the requirement to avoid impacting production.

Answer

Export the database to Cloud Storage and import it into a new instance

Answer

Perform a failover to a read replica and then fail back

Answer

Directly restore a backup to the production database to test recovery time

Question 6

A company has a Cloud SQL for MySQL instance with a cross-region read replica for disaster recovery. During a regional outage, they need to promote the read replica to a standalone instance as quickly as possible. What is the correct procedure?

Accepted Answer

Use the gcloud sql instances promote-replica command on the replica. The correct procedure is to run gcloud sql instances promote-replica on the read replica, which stops replication and makes the replica a standalone, writable instance in its region. This is the fastest supported promotion path and is designed for exactly this DR scenario. After promotion, the instance can accept writes and applications can be redirected to it.

Answer

Create a backup of the replica and restore it as a new instance

Answer

Delete the read replica and restore a backup from the primary as a new instance

Answer

Stop replication on the replica by issuing STOP SLAVE on the instance

Question 7

A service has an SLO of 99.9% availability over 30 days. In the first 10 days, the service has already consumed 60% of the error budget. Which action best aligns with SRE principles?

Accepted Answer

Declare a change freeze and focus on improving reliability. When a service has consumed 60% of its error budget in the first third of the SLO window, the burn rate is significantly higher than sustainable. SRE principles dictate that when the error budget is being consumed too quickly, the team should slow down changes and focus on reliability — typically by declaring a change freeze and investing in reliability improvements. This aligns with the error budget policy, which is a pre-agreed contract that governs release velocity based on budget consumption.

Answer

Ignore the budget and continue deploying as usual

Answer

Extend the SLO window to 60 days to dilute the budget

Answer

Increase the SLO to 99.99% to tighten reliability

Question 8

A Cloud Run service handles HTTP requests that each involve a short background task after the response is sent. The service currently has CPU throttled when not handling requests, causing background tasks to fail. Which configuration change ensures background tasks complete?

Accepted Answer

Set CPU to 'always on'. Cloud Run throttles CPU to near-zero when a request completes unless 'CPU always allocated' (CPU always on) is enabled. Setting CPU to 'always on' keeps CPU available outside request processing, allowing background tasks to complete after the response is sent. This is the specific configuration that addresses post-response background work.

Answer

Set concurrency to 1

Answer

Set execution environment to gen2

Answer

Set min instances to 1

Question 9

An engineer is performing a manual migration from PostgreSQL to Cloud SQL. They run pg_dump and want to import the dump into Cloud SQL. Which pg_dump flags are necessary to avoid errors related to ownership and ACLs?

Accepted Answer

--no-owner and --no-acl. The --no-owner flag prevents pg_dump from setting ownership of database objects to the original owner, which would fail if that role does not exist in Cloud SQL. The --no-acl flag prevents dumping access privileges (GRANT/REVOKE statements), which can also fail if the roles or permissions are not present. Using both flags avoids errors related to ownership and ACLs during import.

Answer

--format=custom and --compress=9

Answer

--schema-only and --data-only

Answer

--create and --clean

Question 10

You need to set up an alert that fires when any of your Compute Engine instances has been down (no metric data) for more than 10 minutes. Which condition type should you use?

Accepted Answer

Metric absent. A 'metric absent' condition in Cloud Monitoring fires when a metric time series stops reporting data for a specified duration. For detecting that a Compute Engine instance has been down (no metric data) for more than 10 minutes, this is the correct condition type because the absence of the metric is the signal itself.

Answer

Metric threshold

Answer

Log match

Answer

Forecast