Business Continuity

DS0-002 · 42 questions

At a small company, database backups are run by hand by whichever DBA remembers at the end of the day. Twice last quarter no backup ran at all, and nobody noticed for several days. Which change best addresses the problem?
A DBA is documenting what each backup type can do on its own. The team takes a full backup every Sunday night. Which statement accurately describes a full backup?
A database receives a full backup every Sunday at 23:00 and an incremental backup every other night at 23:00. The storage fails early Thursday morning before any Thursday backup runs. Which restore sequence recovers the most data from these backups?
A database receives a full backup every Sunday at 23:00 and a differential backup every other night at 23:00. The storage fails early Thursday morning before any Thursday backup runs. Which restore sequence recovers the most data from these backups?
A database keeps its weekly full backup, but the nightly window for the daily backup job is shrinking as data volume grows. The team accepts a longer restore process if each nightly job finishes as quickly as possible. Which daily backup type fits, and what trade-off does it bring?
A nightly backup file is copied from the database server to an off-site storage location over a WAN link that has dropped packets in the past. The DBA needs confidence that the off-site copy is bit-for-bit identical to the original before relying on it. What should the DBA do?
A company has taken nightly database backups for three years, and every job has reported success. During an audit, the DBA admits that no backup has ever been restored. Which practice should the DBA put in place?
At 10:42 a user accidentally deleted several thousand order rows in a production database that uses the full recovery approach with nightly full backups and transaction log backups every 15 minutes. The business wants the data as it was just before the mistake. What should the DBA do?
A DBA must move one schema, including its tables, indexes, views, and data, from a production server to a newer major version of the same database product on a different operating system. The copy must be portable and loadable with standard client tools. Which method fits best?
A DBA manages an 8 TB transactional database with a recovery time objective of four hours. A colleague proposes replacing the nightly physical backups with nightly logical dumps because the dump files are portable. How should the DBA evaluate the proposal?
A DBA notices that a nightly backup job has reported success for the past week, yet each backup file written in that period is zero bytes. The team receives alerts only when a job exits with a failure code. What should the DBA change in the backup reporting and alerting?
A company stores all of its database backups on the same storage array that hosts the production database files, in the same data center. Restores are fast, but an auditor flags a risk. Which change addresses the auditor's concern while keeping fast routine restores?
Regulations require a bank to retain closed-account records for seven years. The records are queried only a few times a year, yet they still sit in production tables and inflate every nightly backup. Which approach best meets the retention requirement while reducing operational load?
Before a major database engine upgrade, a DBA takes a storage snapshot of the database volumes so the team can roll back quickly if the upgrade fails. Which statement about this snapshot is accurate?
A DBA scripted a nightly storage snapshot of a busy database server's data and log volumes. When the team reverted to one snapshot during a test, the database would not start cleanly and reported inconsistencies. Writes were active when the snapshot ran. What should the DBA change?
An auditor asks the DBA team for the document that describes the database system's security requirements, its authorization boundary, and the security controls that are implemented or planned for it. Which disaster recovery planning document is the auditor requesting?
A government contractor must be able to keep its essential business functions running during a disruption that could last weeks, including relocating staff to an alternate facility and defining succession for key roles. Which document should describe these arrangements?
During a disaster recovery exercise, the recovery team must rebuild a database environment from scratch. They need documentation of its architecture, component dependencies, interfaces, and configuration settings. Which document provides this?
A disaster recovery plan lists twelve systems but gives no recovery order. During a test, the team restored the application servers first, and they failed because the authentication and DNS services and the database were not yet available. What should the DBA add to the plan?
A secondary database server is kept up to date by regularly backing up the primary's transaction log, copying each log backup file to the secondary, and restoring it there on a schedule. The secondary can be brought online if the primary fails. Which technique is this?
A primary database ships transaction log backups to a disaster recovery server every 15 minutes, and each file is copied and restored on the secondary shortly after it is taken. If the primary is suddenly destroyed, how much committed data could be lost?
A company's database disaster recovery plan has not been exercised in two years, and several staff named in it have changed roles. Management wants a first test that checks whether the plan's steps, contacts, and assumptions are still valid without any risk to production systems. Which test fits?
During a full disaster recovery test, the team discovers that the database recovery runbook refers to two servers that were decommissioned last year and omits a newer reporting replica. The team improvises and completes the test. What should happen next?
Business owners state that the order-processing database can tolerate losing at most five minutes of committed transactions in any disaster. The DBA currently takes only nightly full backups. Which metric did the business define, and what must change?
An SLA states that the customer portal's database must be back in service within two hours of any outage. The current plan restores from off-site backups, a process the last test timed at six hours. Which metric is the SLA defining, and what does the test result mean?
A retailer's finance director says the checkout database may lose up to one hour of orders in a disaster, but the checkout service must be running again within fifteen minutes. How should the DBA record these objectives?
A fire destroys the primary data center. The order database has an asynchronously replicated secondary in another region that is a few seconds behind. The applications connect through a DNS name that points to the primary. What should the DBA do to restore service?
After a failover, production has run on the disaster recovery server for a week while the original primary was repaired. Management now wants to return operations to the original primary. What must the DBA ensure before failing back?
A company has two systems to protect. A trading platform must resume within minutes of a site failure, whatever the cost. A historical reporting system can be offline for several days, and the budget for it is minimal. Which disaster recovery site approach fits each system?
A customer-facing database must stay available during monthly operating system and database patching, which currently requires a two-hour outage window. Which configuration allows patching with only a brief interruption?
A two-node database cluster was built for high availability. Both nodes connect to one shared storage array, and all of their network traffic passes through a single network switch. Which risk analysis finding is accurate?
A company runs its order database in a single cloud region. Management wants the database to keep serving orders if one data center in that region loses power, and the standby must stay close enough for synchronous commits with low latency. Which design best meets these requirements?
A company operates two data centers 10 km apart connected by dedicated low-latency fiber. The business requires that no committed transaction be lost if the primary database server fails, and it accepts slightly slower commits to achieve this. Which replication mode should the DBA configure?
A retailer replicates its primary database asynchronously to a replica on another continent. Monitoring shows the replica running about 45 seconds behind the primary. The primary site then fails, and the team promotes the replica to keep the business running. What is the most likely consequence of this failover?
A SaaS company serves customers in Europe, North America and Asia from one database region. Distant users report slow page loads caused by read queries, and the business also wants the data to survive the loss of the entire hosting region. Which approach addresses both needs?
A DBA configures database mirroring between a principal server and a mirror server, then adds a third server that holds no copy of the database. The goal is for the mirror to take over automatically if the principal fails. What is the purpose of the third server?
A developer runs a DELETE statement without a WHERE clause on the primary database, and within seconds the rows are also gone from all three high-availability replicas. The manager asks why the replicas did not protect the data and how it can be recovered. Which response is correct?
A database server loses power and restarts. When it comes back online, every transaction that was committed just before the outage is present, and every transaction that was still in progress has been rolled back. Which mechanism makes this recovery possible?
A database uses a recovery setting that keeps every transaction log record until the log is backed up, so that point-in-time restore is possible. The only scheduled job is a nightly full backup. The log disk keeps growing and is now nearly full. Which action correctly resolves the problem?
A design review covers two components: a two-node cluster in the main data center that fails over automatically when a server fails, and nightly backups copied to storage in a second region. The architect asks which component is high availability and which is disaster recovery. Which statement is correct?
A DBA is choosing the RAID level for an eight-disk volume that will hold the data files of a busy OLTP database with heavy random writes. The volume must survive a disk failure, and write performance matters more than usable capacity. Which RAID level best fits?
A two-node database cluster loses the network link between its nodes. Each node concludes the other has failed, promotes itself to primary and accepts application writes, leaving conflicting data on the two nodes. What is this condition called, and what design element prevents it?