Effective database backups are crucial for protecting data integrity and ensuring swift recovery. PostgreSQL 17 introduces a significant upgrade in the form of incremental backups, providing a faster, storage-efficient alternative to traditional full backups.
In this article, you’ll not only learn how incremental backups work in PostgreSQL 17 but also discover why they may completely change the way you approach backup and recovery strategies.
What is incremental backup in PostgreSQL?
An incremental backup captures and stores only the data that has changed since the previous backup was made. This contrasts sharply with full backups, which copy the entire database regardless of how little data has changed. By capturing only incremental differences, PostgreSQL significantly reduces storage demands and shortens backup times, thereby simplifying database operations.
The key benefits of incremental backups are clear:
- Reduced storage requirements: Less data stored means significantly lower costs, especially crucial for enterprises dealing with large databases.
- Faster backup times: Incremental backups process fewer changes, making each backup cycle quicker.
- Simplified operations: Database restoration or cloning is quicker and involves fewer steps.
- Lowered storage expenses: Whether storing backups on-premises or in the cloud, reduced data volume directly translates into lower costs.
How incremental backup works in PostgreSQL
PostgreSQL 17 leverages enhancements to the existing pg_basebackup utility to enable incremental backups. Here’s a breakdown of how this improved mechanism operates:
- Enhanced pg_basebackup utility: A new incremental mode (-i or –incremental) allows users to specify a manifest file from a previous backup, clearly identifying changes since that point.
- Baseline full backup requirement: Incremental backups rely initially on at least one full backup serving as the baseline. This initial backup is taken without the incremental flag.
- Manifest files: PostgreSQL tracks incremental changes using a manifest file generated during backup. The manifest file records data blocks that changed, streamlining incremental tracking.
Here’s the simplified incremental backup workflow:
1. Full backup: Perform the initial backup using:
2. Incremental backup: Subsequent backups capture only changes since the full backup:
3. Continued incremental backups: Future backups reference the most recent incremental manifest file, consistently capturing incremental changes from the latest checkpoint.
Incremental backups step by step
To demonstrate incremental backups clearly, consider the following practical scenario.
Step 1: Prepare database for backups
Create a temporary directory and configure PostgreSQL for incremental backup functionality:
Enable the new WAL summarizer, a PostgreSQL 17 feature designed specifically to reduce unnecessary storage of multiple intermediate data states. Then, prepare your test database:
Step 2: Initial full backup
Perform a full backup that serves as your baseline:
The resulting backup includes PostgreSQL configuration files, data directories, and a special backup_manifest file that tracks this baseline snapshot.
Step 3: Create incremental backups
Next, simulate real-world database changes by inserting additional records into your database:
Now, create your incremental backup referencing the baseline’s manifest file:
You’ll find that the incremental backup folder (inc01) closely resembles the initial full backup, but with a significantly reduced storage footprint, capturing only changes since the previous backup.
Step 4: Validating incremental backups
Inspect the backup_label file within your incremental backup to confirm details:
This file explicitly indicates the incremental nature of the backup, referencing the Logical Sequence Number (LSN) from which it originates.
Restoring incremental backups
Restoring incremental backups in PostgreSQL 17 is straightforward using the newly introduced pg_combinebackup utility. To reconstruct your database, supply the backup directories in the correct chronological order—starting with the full backup followed by incremental backups:
This command consolidates incremental changes into a coherent data directory ready for immediate use.
Incremental backup vs. Point-in-Time Recovery
Traditionally, PostgreSQL provides Point-in-Time Recovery (PITR), allowing restoration of the database to a precise moment using archived Write-Ahead Log (WAL) files. Both incremental backups and PITR restore databases to specific points in time, but differ fundamentally in approach and efficiency:
- Incremental backups only store the final state changes since the last backup, greatly reducing storage space and speeding up recovery times.
- PITR relies on replaying all recorded WAL changes since the last full backup, which may include many redundant intermediate states, thus increasing the size and time needed for recovery.
If your organization’s priority is reduced storage overhead and faster restoration cycles, incremental backups provide an optimal solution. However, for scenarios requiring restoration flexibility down to exact transaction moments, PITR remains essential.
By integrating incremental backups into PostgreSQL 17, developers and administrators now have powerful new tools to optimize storage management, decrease backup times, and streamline recovery operations — essential capabilities for modern enterprise database management.
Let us optimize your PostgreSQL backups
PostgreSQL 17’s native support for incremental backups marks a major leap forward in backup strategy efficiency. By capturing only the changes since the last backup, you dramatically reduce both storage footprint and time to backup, without sacrificing reliability. For organizations managing high-volume systems or seeking to cut operational costs, this feature alone can deliver immediate, measurable benefits.
At ABCloudz, we help companies of all sizes rethink and modernize their PostgreSQL backup and disaster recovery processes. Whether you’re planning a migration, scaling up your infrastructure, or just looking to eliminate inefficiencies, our team is here to help.
Contact us today to schedule a PostgreSQL backup health check or consultation. Let’s make your database safer, leaner, and recovery ready, no matter how complex your workload.
