A database is the cornerstone of any application. For this reason, maintaining one or more backup and recovery options remains a priority for every database professional. There are multiple alternatives you can choose from as per the specific needs of your organization’s database.
In this post, we will examine some of the most popular back-ups and restore strategies for MySQL database and SQL. We will also touch upon the reasons why databases require backups on a regular basis.
Why Do We Need Backups for MySQL Database?
As a DBA, you’ll need backup and recovery to support data in multiple cases, such as:
Discrepancies in Data: Users may accidentally delete or update incorrect data in the primary or replica node.
Data Centre Failure: An indefinite power outage or internet connectivity issue can spell trouble for your organization.
Disk Damage: If the disk is stalling for too long due to some kind of damage, it can greatly reduce performance. In cloud services for Oracle database, it translates into a broken DB instance that cuts access.
Broken Data: In case of a power outage, MySQL may fails to write data and close files as usual. There are also instances where MySQL fails to restart and doesn’t work despite the crash recovery process because of corruption in data.
Legislation/Regulation: Backups and recovery options ensure business value and client satisfaction.
Various Kinds of Backups for MySQL Database
Given below are some common backup categories that suit a range of needs:
Physical: These comprise the exact copies of database files and may contain part or all of the MySQL directory. The most common use of this type of backup is to make a new replica node and respond to host failure in a convenient manner. Experts recommend restoring data with the help of the same MySQL database version.
Offsite: This is one of the most recommended backup alternatives as it guarantees an untouched copy in case of data centre or host failure. It involves copying the data to the cloud, an external file server or another external source. However, sometimes it may take longer to download the files from the cloud or server than the recovery process. Therefore, experienced database professionals keep about a week of data locally on a backup server for quick recovery.
Logical: It is useful for smaller quantities of data as it is slower in comparison to physical backup methods. It essentially consists of dumps from INSERT and CREATE statements. It is useful in addressing data corruption or when you must recover a subset of tables. Although the output is greater in logical backups, especially when that data is present in text format, you can perform a quick compression if the software you’re using requires it. For instance, you can use Mydumper and mysqldump to compress and redirect the data to the zip folder.
Incremental: This type of backup contains all the changes made in the organization’s Oracle database and SQL server since the last backup. It is, therefore, quite useful for enormous datasets since it allows you to take small backups (experts recommend this after you’ve taken a full backup) as data comes later.
Differential: It consists of copying the modifications since your previous backup. One advantage of a differential backup is that it saves disk space. This is because the data in these backups mostly remains the same, so the result leads to backups that are substantially smaller in size.