physical-backup · shipping · also physical backup

Physical database backup

A physical database backup preserves or reconstructs native database files or pages together with the recovery information required by the engine.

Related Observatory article: Physical database backup on hesela.com

Physical describes the stored representation, not whether capture is full or incremental. PostgreSQL 18 pg_basebackup supports both; an incremental result must be combined with its required predecessors before use. [1]

Use an engine-supported capture procedure, not an uncoordinated live file copy. PostgreSQL filesystem backups require shutdown or a documented alternative; running-server snapshots need the complete cluster and required WAL. [2]

Portability is format-specific. PostgreSQL file backups are server-version-specific, while SQLite database files are cross-platform and backward compatible within SQLite 3; forward compatibility is not complete. Check the reader and schema features. [3] [4]

SQLite's Online Backup API copies database pages through an explicit completion protocol. Physical capture is not necessarily offline capture, and completion is separate from application-level restore testing. [5] [7]

Relations

related

Logical database backup, Backup, Full backup, Incremental backup, Backup verification, Restore test, Point-in-time recovery, WAL archiving, SQLite Online Backup API

Advantages

• PostgreSQL base backups provide a native cluster baseline for WAL-based recovery when the required logs are retained. [6]

Limitations

• For PostgreSQL snapshots spanning data, WAL or tablespace filesystems, captures must be simultaneous or use another supported procedure. [2]
• PostgreSQL pg_basebackup includes regular configuration files in the data directory and tablespaces; configuration elsewhere needs separate backup coverage. WAL replay does not restore manual changes to postgresql.conf, pg_hba.conf or pg_ident.conf. [1, 6]

Citations

1. PostgreSQL 18: pg_basebackup, full and incremental cluster capture (accessed 2026-10-29)
2. PostgreSQL 18: File System Level Backup (accessed 2026-10-29)
3. PostgreSQL 18: SQL Dump, comparison with file-level backup (accessed 2026-10-29)
4. SQLite: Single-file Cross-platform Database and compatibility (accessed 2026-10-29)
5. SQLite C API: Online Backup API and completion (accessed 2026-10-29)
6. PostgreSQL 18: Continuous Archiving and Point-in-Time Recovery (accessed 2026-10-29)
7. Hesela: SQLite backup completion and recovery acceptance (accessed 2026-10-29)

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