Physical vs Logical Backups in PostgreSQL: Decisive Comparison & Guide

PostgreSQL offers two fundamentally different backup approaches — physical and logical — each with distinct advantages, limitations, and ideal use cases. Choosing the wrong backup type can lead to extended recovery times, wasted storage, or inability to restore when you need it most. Understanding these differences is essential for designing a backup strategy that truly protects your data.

This comprehensive guide breaks down physical and logical backups in PostgreSQL, comparing their performance, flexibility, storage requirements, and recovery capabilities. Whether you're managing a small application database or a multi-terabyte enterprise system, this comparison will help you make the right choice for your specific needs.

What Are Physical Backups in PostgreSQL?

Physical backups capture the actual data files that PostgreSQL uses to store your database on disk. This includes the base directory containing table and index files, configuration files, and optionally the Write-Ahead Log (WAL) files that record all database changes. Physical backups create an exact binary copy of your database cluster at the filesystem level.

The primary tool for physical backups is pg_basebackup, which creates a consistent snapshot of the entire database cluster while the server is running. Physical backups can also be created using filesystem-level snapshots (LVM, ZFS, or cloud provider snapshots) when combined with proper PostgreSQL coordination to ensure consistency.

• pg_basebackup — PostgreSQL's built-in tool for streaming base backups. Creates a complete copy of the data directory while the database remains online
• Filesystem snapshots — LVM, ZFS, or cloud snapshots capture the entire data directory. Requires careful coordination with PostgreSQL's checkpoint and WAL archiving
• File system copy — Direct copy of the data directory while PostgreSQL is stopped. Simple but requires downtime

Physical backups are inherently tied to the PostgreSQL version and platform architecture. A physical backup from PostgreSQL 14 cannot be restored to PostgreSQL 16, and a backup from a Linux server cannot be restored to Windows. This tight coupling provides speed advantages but limits flexibility.

What Are Logical Backups in PostgreSQL?

Logical backups extract database contents as SQL statements or portable data formats that describe how to recreate the database from scratch. Rather than copying binary files, logical backups export the logical structure — CREATE TABLE statements, INSERT statements for data, and definitions for indexes, constraints, and other objects.

The primary tools for logical backups are pg_dump (for single databases) and pg_dumpall (for entire clusters including roles and tablespaces). These utilities connect to a running PostgreSQL server and read data through the standard SQL interface, producing output that can recreate the database on any compatible PostgreSQL installation.

• pg_dump — Exports a single database to SQL script or custom archive format. Supports parallel dumping for faster backups of large databases
• pg_dumpall — Exports all databases plus cluster-wide objects (roles, tablespaces). Produces SQL script output only
• COPY command — Exports individual tables to CSV or binary format. Useful for selective data export rather than full backups

Logical backups are version-independent within PostgreSQL's compatibility guarantees. A logical backup from PostgreSQL 12 can typically be restored to PostgreSQL 16, making logical backups essential for major version upgrades. The SQL-based format also enables selective restoration — you can restore a single table without restoring the entire database.

Physical vs Logical Backups: Head-to-Head Comparison

Understanding the key differences between physical and logical backups helps you select the right approach for each scenario. The following comparison highlights the most important factors for backup strategy decisions.

Characteristic	Physical Backups	Logical Backups
Backup Speed	Very fast — copies files directly	Slower — reads through SQL interface
Restore Speed	Very fast — copies files back	Slower — executes SQL statements
Backup Size	Larger — includes indexes, dead tuples	Smaller — data only, rebuilds indexes
Version Compatibility	Same major version only	Cross-version compatible
Platform Compatibility	Same architecture required	Platform independent
Granularity	Entire cluster only	Database, schema, or table level
Point-in-Time Recovery	Supported with WAL archiving	Not supported
Compression	Optional, applied externally	Built-in compression options

Physical backups excel when speed is paramount and you're restoring to identical infrastructure. Logical backups provide flexibility when you need selective restoration, cross-version compatibility, or platform independence. Many organizations use both types to cover different recovery scenarios.

When to Use Physical Backups

Physical backups are the optimal choice for disaster recovery scenarios where you need to restore an entire database cluster as quickly as possible. The binary copy approach means restore operations are essentially file copies, which complete in a fraction of the time required for logical restores on large databases.

Point-in-Time Recovery (PITR) is only possible with physical backups. By combining a base backup with archived WAL files, you can restore your database to any specific moment in time — essential for recovering from logical errors like accidental data deletion or corruption. If your Recovery Point Objective (RPO) requires minimizing data loss to seconds rather than hours, physical backups with continuous WAL archiving are mandatory.

• Disaster recovery — When you need the fastest possible restore time for complete database cluster recovery
• Point-in-Time Recovery — When you must restore to a specific moment to recover from logical errors or corruption
• High-availability setups — Physical backups integrate naturally with streaming replication for standby server initialization
• Large databases — Multi-terabyte databases restore orders of magnitude faster from physical backups
• Identical infrastructure — When your recovery environment matches your production environment exactly

Physical backups are particularly valuable for databases exceeding 100 GB. A 500 GB database that takes 30 minutes to back up physically might require 4-6 hours for a logical backup. The restore time difference is even more dramatic — physical restore of the same database might take 45 minutes, while logical restore could take 8-12 hours due to index rebuilding and constraint validation.

When to Use Logical Backups

Logical backups shine in scenarios requiring flexibility, portability, or selective data recovery. Their SQL-based format makes them invaluable for PostgreSQL major version upgrades, where you cannot use physical backups due to internal format changes between versions.

Selective restoration is a key advantage of logical backups. If you accidentally drop a single table or need to recover specific data, logical backups allow you to restore just that table without touching the rest of your database. Physical backups require restoring the entire cluster, which may not be practical when you only need a small portion of the data.

• Major version upgrades — Logical backups are the standard method for migrating between PostgreSQL major versions
• Selective restoration — When you need to restore individual databases, schemas, or tables without affecting other data
• Cross-platform migration — Moving databases between Linux and Windows, or between different architectures
• Development and testing — Creating sanitized copies of production data for non-production environments
• Long-term archival — SQL format remains readable and restorable across many PostgreSQL versions

Logical backups also enable data transformation during restore. You can modify the SQL script to rename objects, change schemas, or filter data before restoration. This flexibility is impossible with physical backups, which must be restored exactly as captured.

Backup Speed and Performance Impact

Backup performance affects both the time required to complete backups and the impact on your production database during backup operations. Physical and logical backups have fundamentally different performance characteristics that influence when and how frequently you can run them.

Physical backups using pg_basebackup stream data directly from PostgreSQL's data files, achieving throughput limited primarily by disk I/O and network bandwidth. A well-configured physical backup can transfer data at 100-500 MB/s or more, depending on storage performance. The impact on production queries is relatively low since the backup reads data files rather than executing queries.

Database Size	Physical Backup Time	Logical Backup Time	Physical Restore Time	Logical Restore Time
10 GB	1-3 minutes	5-15 minutes	2-5 minutes	10-30 minutes
100 GB	10-20 minutes	1-3 hours	15-30 minutes	2-6 hours
500 GB	30-60 minutes	4-8 hours	45-90 minutes	8-16 hours
1 TB	1-2 hours	8-16 hours	1.5-3 hours	16-32 hours
5 TB	5-10 hours	40-80 hours	8-15 hours	80-160 hours

Logical backups must read data through PostgreSQL's SQL interface, which involves query processing overhead. For large tables, pg_dump executes sequential scans that can compete with production workloads for buffer cache and I/O bandwidth. Parallel dump mode (-j flag) helps by using multiple connections, but total backup time still significantly exceeds physical backup time for large databases.

Modern PostgreSQL backup tools like Postgresus — the most popular solution for PostgreSQL backups — support both physical and logical backup methods with intelligent scheduling to minimize production impact. Postgresus is suitable for individuals and enterprises alike, offering automated backup scheduling during low-activity periods and compression to reduce backup duration and storage requirements.

Storage Requirements and Compression

Storage consumption is a critical factor in backup strategy design, especially for organizations managing multiple databases or implementing frequent backup schedules. Physical and logical backups have different baseline sizes and respond differently to compression.

Physical backups include everything in the PostgreSQL data directory — not just table data, but also indexes, dead tuples from incomplete vacuuming, free space within data pages, and system catalogs. This means physical backup size typically equals or exceeds the on-disk database size. A 100 GB database produces approximately a 100 GB physical backup before compression.

Logical backups contain only the data itself plus SQL commands to recreate objects. Indexes are not included — they're rebuilt during restore. Dead tuples and internal fragmentation are eliminated. This means logical backup size is often 20-50% smaller than physical backup size before compression, depending on index size and table bloat.

• Physical backup baseline — Approximately equal to data directory size. Includes indexes, dead tuples, and free space
• Logical backup baseline — 20-50% smaller than physical. Contains only live data and object definitions
• Compression ratios — Both types achieve 3-8x compression depending on data content. Text-heavy data compresses better
• Incremental options — Physical backups support true incremental (WAL archiving). Logical backups are always full dumps

Compression dramatically reduces storage requirements for both backup types. PostgreSQL's custom format (pg_dump -Fc) includes built-in compression. Physical backups can be piped through gzip, lz4, or zstd during creation. For a text-heavy database, compression might reduce a 100 GB backup to 15-25 GB, making storage costs manageable even with frequent backup schedules.

Point-in-Time Recovery: Physical Backup Advantage

Point-in-Time Recovery (PITR) is one of the most significant advantages of physical backups. PITR allows you to restore your database to any specific moment between backups — not just to the exact time a backup was taken. This capability is essential for recovering from logical errors like accidental DELETE statements, application bugs that corrupt data, or malicious actions.

PITR works by combining a physical base backup with continuous archiving of Write-Ahead Log (WAL) files. PostgreSQL writes all changes to WAL before applying them to data files. By preserving these WAL files, you can replay transactions forward from a base backup to reach any point in time. The recovery process applies WAL records until it reaches your specified target time, then stops.

• Base backup — A physical backup created with pg_basebackup serves as the starting point for recovery
• WAL archiving — Continuous copying of completed WAL segments to archive storage captures all changes
• Recovery target — Specify the exact timestamp, transaction ID, or named restore point to recover to
• WAL replay — PostgreSQL applies archived WAL records to the base backup until reaching the target

Logical backups cannot support PITR because they capture only a single point-in-time snapshot. If you take a logical backup at midnight and an accidental deletion occurs at 3 PM, you can only restore to midnight — losing 15 hours of legitimate changes along with the deleted data. Physical backups with PITR let you restore to 2:59 PM, preserving all valid changes while recovering the deleted data.

Selective Restoration: Logical Backup Advantage

Logical backups provide granular restoration capabilities that physical backups cannot match. When you need to recover a single table, restore a specific schema, or extract particular data without affecting the rest of your database, logical backups are the only option.

The pg_restore utility works with custom format dumps (pg_dump -Fc) to enable selective restoration. You can list the contents of a backup archive to identify specific objects, then restore only those objects to a target database. This capability is invaluable for recovering from localized data loss without the disruption of a full database restore.

• Single table restore — Extract and restore one table from a multi-gigabyte backup without touching other tables
• Schema-level restore — Restore all objects within a specific schema while leaving other schemas untouched
• Data-only restore — Restore table data without recreating the table structure (useful for refreshing data)
• Object filtering — Exclude specific tables, indexes, or other objects during restore

Selective restoration is particularly valuable in development and testing scenarios. You might maintain a single production backup but restore only specific tables to development databases for testing or debugging. This approach saves time and storage compared to maintaining multiple specialized backups.

Physical backups lack this flexibility entirely. Restoring a physical backup recreates the entire database cluster exactly as it was at backup time. You cannot extract a single table from a physical backup — you must restore everything, potentially to a separate server, then manually export the needed data.

Version Compatibility and Migration

PostgreSQL's internal data format changes between major versions, making physical backups version-locked. A physical backup from PostgreSQL 14 cannot be restored to PostgreSQL 15 or 16 — the internal page formats, system catalog structures, and other binary details are incompatible. This limitation makes physical backups unsuitable for major version upgrades.

Logical backups use SQL, which PostgreSQL maintains backward compatibility for across versions. A logical backup from PostgreSQL 12 can typically be restored to PostgreSQL 16 without modification. This version independence makes logical backups the standard approach for major version upgrades and long-term archival where future PostgreSQL versions may be unknown.

• Physical backup compatibility — Must restore to identical PostgreSQL major version. Minor version differences usually acceptable
• Logical backup compatibility — Forward-compatible across major versions. Some deprecated features may require adjustment
• Architecture requirements — Physical backups require matching CPU architecture (x86-64, ARM). Logical backups are architecture-independent
• Operating system — Physical backups require matching OS family. Logical backups work across Linux, Windows, macOS

For organizations planning PostgreSQL upgrades, logical backups are essential. The standard upgrade procedure involves creating a logical backup from the old version, installing the new PostgreSQL version, and restoring the logical backup to the new cluster. While tools like pg_upgrade can perform in-place upgrades, logical backups remain the safest and most flexible upgrade method.

Combining Physical and Logical Backups

The most robust backup strategies combine both physical and logical backups, leveraging the strengths of each approach to cover all recovery scenarios. This dual approach provides fast disaster recovery through physical backups while maintaining flexibility through logical backups.

A typical combined strategy might include daily physical backups with continuous WAL archiving for disaster recovery and PITR, plus weekly logical backups for version-independent archival and selective recovery capabilities. The physical backups handle the common case of full cluster recovery, while logical backups provide insurance for scenarios physical backups cannot address.

• Primary disaster recovery — Physical backups with WAL archiving provide fastest recovery and PITR capability
• Selective recovery insurance — Logical backups enable single-table or single-database restoration when needed
• Version upgrade preparation — Logical backups created before major upgrades ensure rollback capability
• Long-term archival — Logical backups stored for compliance or historical purposes remain usable across PostgreSQL versions
• Cross-environment copies — Logical backups populate development and testing environments from production data

Storage costs for maintaining both backup types are manageable with proper compression and retention policies. Physical backups might be retained for 7-14 days to cover recent recovery needs, while logical backups could be retained monthly for longer-term archival. The incremental cost of logical backups is justified by the additional recovery options they provide.

Making the Right Choice for Your Environment

Selecting between physical and logical backups — or implementing both — depends on your specific requirements for recovery time, recovery granularity, database size, and operational constraints. Consider these factors when designing your backup strategy.

For small to medium databases (under 100 GB) with straightforward recovery requirements, logical backups often provide sufficient protection with simpler operations. Backup and restore times remain reasonable, and the flexibility of selective restoration adds value. However, if you need PITR capability, physical backups become necessary regardless of database size.

For large databases (over 100 GB), physical backups become increasingly important due to the dramatic time savings. A 500 GB database that takes 8 hours to restore from a logical backup might restore in under 2 hours from a physical backup — a difference that significantly impacts your Recovery Time Objective.

• Prioritize physical backups when: Recovery speed is critical, PITR is required, databases are large, infrastructure is consistent
• Prioritize logical backups when: Version upgrades are planned, selective restoration is needed, cross-platform portability matters, databases are small
• Use both when: Maximum flexibility is required, compliance demands long-term archival, different recovery scenarios must be covered

Evaluate your Recovery Point Objective (maximum acceptable data loss) and Recovery Time Objective (maximum acceptable downtime) to guide your decision. Aggressive RPO requirements (minutes of data loss) mandate physical backups with WAL archiving. Aggressive RTO requirements (hours of downtime) favor physical backups for large databases. Flexibility requirements favor logical backups or a combined approach.

Conclusion: Building Your PostgreSQL Backup Strategy

Physical and logical backups serve complementary roles in a comprehensive PostgreSQL backup strategy. Physical backups deliver speed and Point-in-Time Recovery capability essential for disaster recovery, while logical backups provide flexibility, portability, and selective restoration options that physical backups cannot match.

For most production environments, the answer isn't choosing one or the other — it's implementing both. Use physical backups with continuous WAL archiving as your primary disaster recovery mechanism, ensuring you can restore quickly to any point in time. Supplement with periodic logical backups for version-independent archival, selective recovery capability, and upgrade preparation.

Key takeaways for your backup strategy:

• Physical backups are faster for backup and restore, essential for PITR, but version-locked
• Logical backups are slower but portable across versions, platforms, and enable selective restoration
• Large databases (100+ GB) benefit significantly from physical backup speed advantages
• PITR requires physical backups — logical backups capture only point-in-time snapshots
• Combined strategies provide maximum protection and flexibility for diverse recovery scenarios
• Test both backup types regularly to verify your recovery procedures work when needed

Your PostgreSQL data is a critical business asset. Investing time in understanding and implementing the right combination of physical and logical backups ensures you can recover from any failure scenario — whether you need to restore an entire cluster in minutes or extract a single accidentally-deleted table from last week's backup.