In this post you will learn about Netezza backup and restore data. It provides general information on backup and restore methods available with Netezza system.
Netezza Backup and Restore Overview
Netezza provides several backup and restore methods as per the different requirements. You can take table or database backup whenever required:
- You can create full and incremental backups of your various Netezza databases in compressed internal using the nzbackup command and restore them to a Netezza system whenever required using nzrestore command. As a best practice create script that perform the full and incremental backup and schedule the same.
- Unload individual table’s data in compressed internal format using the CREATE EXTERNAL TABLE command, later you can load the data using the nzload command.
- You can also unload the individual table in text formats using CREATE EXTERNAL TABLE available in Netezza.
- You can create backups of the system catalog (the /nz/ directory) on the Netezza host using the nzhostbackup command. Later, in case of data corruption, you can restore using nzhostrestore command.
Netezza Backup Types
There are different kinds of backup options available:
Read:
- Netezza External Table
- Export Netezza Table to CSV Format
- nzsql Command and its Usage
- Commonly used Netezza Basic Commands
Netezza Full Backup
This process backup full database every time you run it.
For example, to backup contents of database DB1 to directory /mnt/data/backups:
nzbackup -dir /mnt/data/backups -u user -pw password -db DB1
Incremental Backups
Incremental backups are database backups that save only the data that changed since the last backup
Netezza supports two types of incremental backups:
Differential Backup
This backup type includes all the changes that are made to the database since the previous full, differential or cumulative backup. You should have full backup of the database before using differential backup option.
nzbackup -dir /mnt/data/backups -u user -pw password -db DB1 –differential
Cumulative Backup
This backup type includes all the changes that are made to the database since the last full backup. Cumulative backups consolidate and replace any differential backups that were run since the last full backup.
nzbackup -dir /mnt/data/backups -u user -pw password -db DB1 -cumulative
Below figure shows the sample backup process: A- Full Backup, B- cumulative and C-series of differential backups:
Netezza Backup and Restore Best Practices
- Create script that executes the recommended backups and schedule it to perform backup.
- The following backups are recommended on a weekly basis:
- nzhostbackup (requires a system Pause)
- nzbackup -globals -dir /path/to/storage
- A FULL backup of each user database should be taken regularly weekly, bi-weekly, or monthly.
- A differential backup of each user database should be taken daily.
Netezza Restore Examples
Finally, you can restore the Netezza database by using nzrestore command: For example,
nzrestore -db db1 -u user -pw password -dir /mnt/data/backups -v