database backup and recovery
0 likes1,166 views
The document discusses database backup and recovery techniques. It defines database backup as backing up the operational state, architecture and stored data of a database to create a duplicate instance in case of crashes or data loss. It describes different backup methods like transaction log backups and full backups. It also discusses the importance of backups to restore data after damage or deletion. The document then covers different types of backups like full, incremental and differential backups. It further discusses database recovery, causes of database failures, and solutions like log-based recovery and shadow paging. Finally, it discusses the importance of backups and recovery for business continuity.
Ad
More Related Content
What's hot (20)
Similar to database backup and recovery (20)
![[db tech showcase Tokyo 2015] D25:The difference between logical and physical...](https://cdn.slidesharecdn.com/ss_thumbnails/dbts-tokyo-2015d25oracledbvisit-software-150619090737-lva1-app6891-thumbnail.jpg?width=560&fit=bounds)
Ad
More from sdrhr (12)
Ad
Recently uploaded (20)
database backup and recovery
- 2. Post.Graduate Govt Gulberge College For Women,Lahore Subimitted to: Ma'am Furwa Ali Submitted by: Sidra Tahir 1922110043 Alisha 1922110002 NidaFfatima 1922110027 Tyyaba 1922110047 Nayyab Mir 1922110025 Aneela 1922110006 Ruqia Naz 1922110032 Taimul Tosha 1922110046 Areeka 1922110009 Sawera 1922110039 Subject: Database Managment System Department: BS(COMPUTER SCIENCE) Session : 2019-2023 Presentation Topic: OVERVIEW OF DATABASE BACKUP AND RECOVERY TECHNIQUES
- 4. Definition: • Database backup is the process of backing up the operational state, architecture and stored data of database software. It enables the creation of a duplicate instance or copy of a database in case the primary database crashes, is corrupted or is lost. Examples: • User error • Hardware failure • Catastrophic event
- 5. How we can backup of data in database: • The different methods of backup in a database are: • Transaction log • Full Backup • Diffrential backup Why we need database backup? Backups help to restore computer devices during the process of disaster recovery and restore data after files have undergone damage or deletion. Database backups are essential for protection against data loss that can completely disrupt business operations.
- 7. Full backup As the name implies, a full backup is when every single file and folder in the system is backed up. A full backup takes longer and requires more space than other types of backups but the process of restoring lost data from backup is much faster. Incremental backup With incremental backup, only the initial backup is a full one. Subsequent backups only stores changes that were made since the previous backup. The process of restoring lost data from backup is longer but the backup process is much quicker. Differential backup Differential backup is similar to incremental backup. With both, the initial backup is full and subsequent backups only store changes made to files since the last backup. This type of backup requires more storage space than incremental backup does, however, but it also allows for a faster restore time.
- 8. Error inBackup Whatiserrorinbackup? ❖ There is a failure in preparing the backup image of one of the volume in the backup set. ❖ If specified file or data is not found while restoring a data in full backup is called Error in backup. ❖ ailure in preparing the backup image of one of the volume in the backup set. ❖ If specified file or data is not found while restoring a data in full backup is called Error in backup.
- 9. Common Causes Of Error
- 10. Media Failure ● Failure of disk drive ● Failure of disk controller ● Deletion or curruption of database file Infrastructure Failure ● Tape disk ,libraries ● disk arrays and backup server and network can faier ● Deletion or curruption of database file
- 11. Software updates ● Incompatibilities between backup software and new version of applications Human Error ● Invalid path ● Deciding inconsistent device to store data in spite of recommented device Cyberattacks ● Hackers can delete data
- 13. Database recovery: Definition: Database recovery means recovering the data when it get deleted , damaged or hacked accidentally. part 2
- 14. Explanation: 1. Database recovery comes in the limelight when data loss takes place due to certain factors which includes accidental , deleting data , partition loss , window reinstalltion accidental formatting of the hard drive. 2. Data recovery software will recover the hard to access data even if the storage device has stopped working.
- 15. Causes of recovery: 1. Electro mechanical failure 2. Natural disaster 3. Computer virus 4. Data corruption 5. Computer crime 6. Human error
- 16. TYPES OF DATABASE FAILURE System failure Hardware failure Tansaction failure Add your words here Software failure
- 17. 1 Hardware failure Hardware failure may include: . Memory errors . Disk sectors . Disk fuul errors . Disk craches 2 Software failure Software failure may include failure related to software's such as . Operating system . DBMS software( MY SQL, IBM ,FOX PRO, DB2, ORACLE)etc. . Application software
- 18. 3 System failure System craches due to: .Hardware .Software error, resulting in the loss of main memory 4 Recovery from transaction failure means that the database is restored to the most recent consistent state just before the time of failure to do this, the system must keep information obout the change that were applied to data items by the various transaction, this information is kept in system log. backup transaction recovery
- 19. Solution Of Database Failure Stable Storage: stable storege is a storage where we can store same data more then one computer if one computer is damage because of some reasons than we can restore data with the help of remaining computers. pc 1 pc 2 pc 3
- 20. Performance of recovery techniques:- 1.Log based recovery 2.Shadow paging
- 21. Log based recovery:- • Log is a sequence of log records, recording all the update activities in DB. • Fields:- • #Transaction Identifier: T start • Data item identifier: T X,10,15 • Old value: T abort (X=10) • New value: T commit (X=15)
- 22. Transaction. Log • (a=b=1000) • To:read(a) • a=a-50 • Write(a) • Read(b) • b=b+50 • Write(b) • To start • To a,1000,950 • To b,1000,1050 • To commit
- 23. Shadow paging:- • It is a technique used to achieve the atomic and durable transactions and provides the ability to manipulate pages in a database. • In shadow paging,need to maintain 2 pages table: • Current page table. • Shadow page table. • When transactions begin,the current page is copied to shadow page.(Both page table are identical.) • The current page table copy data to shadow page and then it copy it to disk.
- 24. Why Backup and Recovery is important Backup copies allow data to be restored from an earlier point in time to help the business recover from an unplanned event. Storing the copy of the data on separate medium is critical to protect against primary data loss or corruption.
- 25. Backup and Recovery with RMAN The most noteworthy are: Incremental backups, which provide more compact backups (storing only changed blocks) and faster datafile media recovery (reducing the need to apply redo during datafile media recovery) • Block media recovery, in which a datafile with only a small number of corrupt data blocks can be repaired without being taken offline or restored from backup • Unused block compression, where RMAN can in some cases skip unused datafile blocks during backups • Binary compression, which uses a compression mechanism integrated into the Oracle database server to reduce the size of backups • Encrypted backups, which uses encryption capabilities integrated into the Oracle database to store backups in an encrypted format
- 27. Definition: “Data definition language is a type of SQL language.It is used to create and modify the structure of dba object in database.These database object includes views,schema,table,indexes etc. Purposes and uses of ddl: • It is used to describe the fields and record in db table. • Ddl are the sets of commands which are used to create,update,delete,structure of db. • These commands are not for end users but used by db designer and DBA.
- 28. Example: EMPLOYEE ID NO. ENAME AGE CITY 1 ali 45 lahore
- 29. FUNCTIONS OF DDL DDL(Data Definition Language) : DDL or Data Definition Language actually consists of the SQL commands that can be used to define the database schema. It simply deals with descriptions of the database schema and is used to create and modify the structure of database objects in the database. Examples of DDL commands: CREATE – is used to create the database or its objects (like table, index, function, views, store procedure and triggers). DROP – is used to delete objects from the database. ALTER-is used to alter the structure of the database. TRUNCATE–is used to remove all records from a table, including all spaces allocated for the records are removed.