Backup and Restore
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Backup and Restore
Backup and restore in SQL refers to creating copies of database data (backup) and recovering it when needed (restore). It is essential for data protection and disaster recovery.
Syntax
-- Backup (MySQL example)
mysqldump -u username -p database_name > backup.sql
-- Restore
mysql -u username -p database_name < backup.sql;📝 Edit Code
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What is Backup?
- 1Copy of database data.
- 2Used for recovery.
- 3Prevents data loss.
- 4Can be full or incremental.
What is Restore?
- 1Process of recovering data.
- 2Uses backup files.
- 3Restores database state.
- 4Used after failure or loss.
Types of Backup
- 1Full backup - complete database.
- 2Incremental backup - changes only.
- 3Differential backup - changes since last full backup.
- 4Log backup - transaction logs.
Backup Tools
- 1mysqldump (MySQL).
- 2pg_dump (PostgreSQL).
- 3SQL Server Backup Utility.
- 4Cloud backup services.
Advantages
- 1Prevents data loss.
- 2Supports disaster recovery.
- 3Ensures business continuity.
- 4Helps in migration.
Limitations
- 1Requires storage space.
- 2Time-consuming for large databases.
- 3Needs regular maintenance.
- 4May affect performance during backup.
Real-world
- 1Recovering from system crashes.
- 2Protecting against data loss.
- 3Migrating databases between servers.
- 4Testing environments setup.
- 5Disaster recovery planning.
Common Mistakes
- 1Not taking regular backups.
- 2Storing backups in same server.
- 3Ignoring restore testing.
- 4Using outdated backup files.
Best Practices
- 1Schedule regular backups.
- 2Store backups in secure locations.
- 3Test restore process frequently.
- 4Use automated backup tools.
Quick Summary
- Backup creates a copy of database data.
- Restore recovers data from backup.
- Essential for disaster recovery.
- Supports full and incremental backups.
- Must be done regularly for safety.
Interview Questions
Q1. What is database backup?
Answer: A copy of database data used for recovery.
Q2. What is restore in SQL?
Answer: Recovering database from backup files.
Q3. Why is backup important?
Answer: To prevent data loss and ensure recovery.
Q4. What are types of backup?
Answer: Full, incremental, differential, and log backups.
Q5. Should backups be tested?
Answer: Yes, restore testing is essential.
Quiz
What is the main purpose of database backup?