DS0-001 Practice Test 3 — 10 Questions

Question 1

A database is experiencing high I/O wait times on the log drive. What is the most effective configuration change to alleviate this bottleneck?

Accepted Answer

Move the log to a high-performance dedicated drive. Moving the transaction log to a dedicated physical drive with high write performance (low latency) is the most effective way to resolve I/O bottlenecks related to transaction logging.

Answer

Use data compression

Answer

Increase the buffer pool size

Answer

Reduce the database recovery interval

Question 2

A database developer needs to combine the results of two different SELECT queries into a single result set. Which operator should be used?

Accepted Answer

UNION. The UNION operator is specifically designed to combine the result sets of two or more SELECT statements into one.

Answer

JOIN

Answer

CONCAT

Answer

MERGE

Question 3

Which THREE of the following are benefits of database indexing?

Accepted Answer

Enforcement of uniqueness. Indexing speeds up data retrieval, improves JOIN performance, and aids in uniqueness enforcement.

Answer

Faster write operations

Answer

Reduced storage requirements

Question 4

You are migrating an on-premises Oracle database to Oracle Cloud Infrastructure (OCI) using a tool that requires the least amount of downtime while keeping the source and destination databases in sync. Which method should you select?

Accepted Answer

Implement Oracle GoldenGate for continuous logical replication.. Oracle GoldenGate allows for real-time data replication, which is ideal for minimizing downtime during migrations.

Answer

Perform a cold backup and restore to an OCI block storage volume.

Answer

Use Data Pump Export/Import with manual application of incremental backups.

Answer

Use SQL Developer to manually generate and execute insert scripts for all tables.

Question 5

A query is slow due to excessive scanning of a large table. The execution plan shows a 'Table Scan'. What is the most likely missing element?

Accepted Answer

An index. A Table Scan occurs when the database must read every row; an index would allow it to find data more efficiently.

Answer

A view

Answer

A stored procedure

Answer

A trigger

Question 6

A database architect is setting up an Always On Availability Group in SQL Server. To ensure that the secondary replica can be used for read-only workloads without impacting the primary node's performance, how should the 'Readable Secondary' property be configured?

Accepted Answer

Set to 'Read-intent only' to allow access based on application connection strings.. The Readable Secondary property allows you to designate which replicas accept read-only connections. Setting this to 'Read-intent only' is a common practice for offloading read-only reporting queries.

Answer

Set the synchronous commit mode to 'Asynchronous' on all nodes.

Answer

Set to 'Yes' and force all writes through the secondary replica.

Answer

Set to 'No' and route traffic via a secondary listener.

Question 7

Which document is essential to establish the legal basis for processing personal data under GDPR between a controller and a processor?

Accepted Answer

Data Processing Agreement (DPA). A Data Processing Agreement (DPA) is a mandatory contract under GDPR that specifies the responsibilities of the data controller and the data processor.

Answer

Service Level Agreement (SLA)

Answer

Acceptable Use Policy (AUP)

Answer

Data Privacy Impact Assessment (DPIA)

Question 8

A company needs to audit all administrative actions taken on their database server. Which feature should the DBA enable?

Accepted Answer

Database Audit Logging. Database Auditing logs all DDL and DML operations, providing the evidence needed for compliance reporting.

Answer

Data Partitioning

Answer

Query Optimization

Answer

Transaction Log Backup

Question 9

When working with time-series data, what does a 'lag' feature represent in an analysis?

Accepted Answer

The value of a variable from a previous period. A lag feature represents the value of a variable at a previous time step, which is useful for trend analysis.

Answer

The time taken to query the data

Answer

The difference between two time stamps

Answer

The sampling rate of the sensors

Question 10

A company is using a cloud-based data lake. To satisfy data sovereignty requirements, they must ensure data remains in a specific region. How can this be enforced?

Accepted Answer

Regional Resource Policies. Cloud providers use resource location constraints and policy-based tags to restrict where data can be physically stored.

Answer

Database Load Balancing

Answer

Database Indexing

Answer

Data Compression