How can you recover from a database outage without losing data?

The primary objective of backup and recovery is to protect the integrity of business-critical data and restore operations swiftly in the event of data loss Making backups of collected data is critically important in database system. Backups protect against human errors, hardware failure, virus attacks, power failure, and natural disasters

- Preplan your Disaster Recovery, Backup and Restore and Business Continuity plans when working on projects. - Backups can be periodic/continuous with full/incremental/snapshots. - The chosen backup is stored in some location and you need to know/configure how long you should keep it. This is retention period. - What backup and restore strategies choose when? depends on your use-case. - Be it on-premises or Cloud, Errors/accidents/disasters/downtimes can occur and will occur. So having a solid backup and restoration strategy will help with minimal down-time. - Having a standby database as part of your Disaster Recovery plan helps a lot. You can achieve no down-time with this. Everything depends on your budget constraints also.

There are few main reasons why backup and recovery is very important 1. Minimize downtime in case of data loss or system failure 2. Protection from any ransomware attacks 3. Quick data recovery from human errors 4. To meet the organization compliance standards

It's absolutely crucial for safeguarding your valuable data and ensuring uninterrupted operation. * Protecting against data loss * Enabling disaster recovery * Supporting routine maintenance * Compliance requirements If we don't have valid backups in place, then in case of any issue/disaster we may not be able to recover back and we must face a data loss.

Data backup and recovery is creating and storing backup copies of data to safeguard businesses from data loss due to breaches, external attacks, software crashes, and hardware failures. All businesses and organizations today are susceptible to many data threats. An organization may suffer irreversible data loss if it does not have good data backup strategies. Negligence can lead to financial losses, customer distrust, and legal consequences

1. Backup Types: Choose between full, incremental, or differential backups based on your recovery time objectives (RTO) and recovery point objectives (RPO). 2. Frequency: Determine how often backups should be performed based on the criticality of your data. 3. Retention Policy: Establish a retention period for backups 4. Storage Location: Decide whether to store backups on-premises, in the cloud, or a combination of both, considering accessibility and security.

Indeed, isolating backups on storage without network access is a crucial strategy to enhance security and protect against ransomware attacks. This ensures that even if the network is compromised, the backup data remains untouched and available for recovery. It's a valuable precautionary measure to safeguard critical information and maintain resilience against potential security threats.

Full backup is a standalone copy, allowing for independent restoration without reliance on other backups. Incremental backups only capture changes made since the last backup, reducing storage space requirements. 1. In a scenario when there is entire data refresh then we can go for full backup ensuring the integrity of critical data. 2. Few scenarios when the DB experiences frequent changes, and capturing only the changes made since the last backup using incremental is sufficient.

There are numerous angles we have to look on, like in SQL Server we have to first check the recovery model of the databases. In case of Full and bulk log recovery model only we can take full, differential and Tlogs backups that can be used to do point in time recovery. As in case of simple recovery model Tlog backups cannot be taken hence the point in time recovery is not possible. We have multiple type of backups available in SQL Server - *Full Backup *Differential Backup *Transaction log Backups *Tail Log Backup *Copy only Backup *Filegroup Backup *Compressed Backup

Class database by size is a good starting point under 100gb we can probably perform full backups over that we probably enter incremental territory. Also the windows backup can run to not interfere with application performance. Irrespective of full or incremental the transition logs should be backed up with a regular cadence to best satisfy RPO.

I think this generally depends upon the size of the companies database estate and range of vendors you they have. For smaller companies databases native tools coupled with o/s backup solution generally suffice. For larger estates with many database vendors they may want to look at a database agnostic solution.

One crucial checklist for DBAs involves ensuring the health of database backups, often overlooked. Validation can be done in two ways: 1. Frequent use of the VERIFYONLY option to assess backup health. 2. Quarterly restoration of a complete backup to ensure overall health, tailored to criticality considerations. Certainly, validating backups for large databases can be time-consuming and resource-intensive, impacting both time and cost. Balancing the frequency and methods of validation is crucial to find a practical compromise that ensures data integrity without excessively burdening resources. It's essential to weigh the benefits of validation against the associated costs & choose a strategy that aligns with the organization's priorities.

There are DBAs those avoid validating the backup. I have also seen the scenarios where recovery of the database is needed, and backup files required for the same is not valid which leads to the data loss. Below command will check the backup file and return a message of whether the file is valid or not. If it is not valid, this means the file is not going to be useable for a restore and a new backup should be taken. RESTORE VERIFYONLY FROM DISK = 'D:\Database.BAK'

In experience, only restoring and quering the database backup in a test environment might be misleading The best practice would be to setup a full replica of the system (front end and backend) and regularly restore database backups to it. This will enanle one to run automated and simulated tests on the database and interactivity between front-end controllers and db models Any failures will point to either restoration issues or help to quickly identify faults / bugs in the live system

Backup testing if possible should be performed if possible daily, weekly or monthly to facilitate a break fix environment in a lower tier environment or even to suit project requirements, the larger the databases the more problematic this becomes, also a shift to thin provisioned restores has a negative impact that backups are nolonger used it used less for above requirements.

The best strategy is not only having a good backup, but having a spare/standby database ready to become your primary. With such architecture you are protected from data loss, the database can be brought online quickly and without much effort. With Oracle databases we usually configure one or more standby databases using DataGuard. We can even use Active DataGuard to open the standby databases in read-only mode to serve as a read-replica for the applications. In a DR scenario the failover to one of the standby databases can be automated by using Fast-Start Failover (FSFO) feature or can be done manually by issuing the "failover to <site-b-db>" or in certain occasions "failover to <site-b-db> immediate" commands from DGMGRL.

Absolutely, while proper backup strategies address database outages, a comprehensive approach involves Disaster Recovery (DR). DR ensures data availability with minimal Recovery Point Objective (RPO) and Recovery Time Objective (RTO). Various techniques tailored to the database stack can be employed, enhancing resilience and minimizing downtime in the face of unforeseen disruptions.

Assuming you have regular full db level backups, a full restoration to the last good configuration should be the ideal solution. However, you can also rely on replication environments to restore your data from secondary to primary In the worst case scenario, you will have to rebuild the database using transaction logs

1. Consider the minimum recovery possible. On large systems it may be possible to recover only a small number of corrupted/lost files and roll forward from transaction/redo/wal logs already present on the system. 2. In the case of a point in time recovery to hit your RPO, don't underestimate the time it takes to both recover the transaction/redo/wal logs - and apply them. The only way to understand how long this take is to test it.

I once recovered from backup using the server we had built as a “sandbox”, and actually made that the live server after restoring backups to that. As others have noted, most of the time you are probably trying to recover at the server level, and not just restoring a backup to the same server.

In most cases, organisations run very comprehensive backup and recovery strategies. However, the grey area usually lies around the rotation and/or isolation of the backups from the live system. In most cases, the two are either directly connected through live media (ethernet or USB) or rely on human intervention, without intermediate testing to check for corruption, malware, degradation, etc This means most organisations only detect issues, when they're hit by a crisis and need to restore to a backup. In the event of ransomware, this is catastrophic!

Short answer - Have a flawless DR strategy. Here is how : RTO/RPO requirements are one of the key design considerations to design robust database system. That's the first step. While building database system, you would want to consider various backup and recovery methods such as backup and restore, pilot light setups, warm standby, active-active setup etc. and carefully assess and even customize them to achieve desired RTO and RPO fit. Second step is to implement the winning backup and recovery methodology from step 1. Third step is to test implemented backup and recovery processes periodically to ensure their effectiveness. These are very important steps to avoid data loss during inopportune outages.

Use transaction logs to record changes made to the database. Transaction logs enable recovery to a specific point in time before the outage occurred, reducing the risk of data loss.

Backup Encryption Backup Compression Backup Validation Regular Restore Tests We must consider the type of storage as well so that the backup must be faster.

Use transaction logs to record changes made to the database. Transaction logs enable recovery to a specific point in time before the outage occurred, reducing the risk of data loss.