Evaluate your understanding of key methods and best practices for backup and restoration in CouchDB environments. This quiz covers essential concepts, techniques, and considerations for maintaining data safety and reliability in document databases.
Why is it important to regularly perform backups in a CouchDB environment?
Explanation: Regular backups safeguard data against accidental loss, corruption, or failure, allowing you to restore information if problems occur. Backups do not increase query speed, which involves optimization rather than duplication. Preventing replication is not related to backups; it is managed separately. Reducing database size is generally achieved through compaction or archiving rather than by backing up data.
Which method is commonly used to create a simple backup of a CouchDB database?
Explanation: Creating a backup via HTTP GET request involves downloading all documents, typically using tools like curl to retrieve the database content in JSON format. Deleting documents would result in data loss rather than a backup. Changing the file extension does nothing to preserve database contents. The VACUUM command is not a feature in CouchDB; it applies to other database systems.
How often should you schedule backups for a production CouchDB, assuming frequent data changes?
Explanation: Backups should be scheduled regularly in line with how often your data changes to minimize possible data loss. Backing up only once during deployment is risky and insufficient. Waiting five years between backups is inadequate for any active data environment. Performing a backup only after a crash is too late to preserve lost data.
When restoring data to a CouchDB database, what is a typical approach to avoid overwriting existing important documents?
Explanation: Restoring to a new database allows careful comparison and merging of documents, minimizing risk of overwriting. Overwriting the live database can result in permanent loss of vital data. Randomly renaming backup files does not protect data integrity. Deleting the current database before restoring may cause loss if the process fails or if the backup is incomplete.
What is the typical format for exporting CouchDB documents for backup purposes?
Explanation: CouchDB stores and transfers documents in JSON format, making it suitable for backups and restores. CSV files are better for structured, tabular data but not for complex documents. PDF and XLS formats are used for reports and spreadsheets, not for database document storage or transfers.
Which strategy can help manage backups efficiently in CouchDB with very large databases?
Explanation: Incremental backups using the changes feed allow you to back up only the changes since the last backup, saving time and storage. Backing up just view indexes misses the actual document data. Ignoring attachments may result in incomplete data. Disabling compaction before backup does not improve backup efficiency and can lead to larger files.
After restoring a CouchDB database from a backup, what is an essential validation step?
Explanation: Validating the restore involves checking that document counts match and reviewing sample data for accuracy, ensuring the process was successful. Upgrading user passwords, changing ports, or uninstalling extensions are unrelated to data validation after a restore. Ensuring restored data matches expectations is key to confirming backup integrity.
Where should you ideally store CouchDB backups to maximize data safety?
Explanation: Storing backups on separate, offsite storage protects your data from local disasters such as hardware failure, theft, or fire. Using the same disk exposes backups to the same risks as the primary data. Temporary folders are vulnerable to deletion or system cleanup, and system clipboards cannot store large or persistent backups.
What effect does running compaction in CouchDB before taking a backup have?
Explanation: Compaction removes outdated and deleted document revisions, resulting in smaller, cleaner backups. It does not delete indexes, which are maintained separately. User authentication data and encryption are not affected by compaction; these are managed through other processes.
What should you ensure when backing up CouchDB databases that contain document attachments?
Explanation: Ensuring attachments are backed up is vital so that documents retain all necessary files and information when restoring. Log files are for troubleshooting, not for restoring document data. Excluding attachments leads to incomplete backups. Changing attachment formats is unnecessary and may complicate recovery.