Spatial Data Versioning
Definition
Spatial data versioning manages changes to geospatial datasets over time, allowing edits to be tracked, reviewed, merged, and rolled back. Techniques include long transactions, branching and merging for multi‑user editing, delta storage for efficient history, and immutable snapshots for auditing. Versioning covers both vector and raster data and must consider spatial topology and performance at scale.
Application
Mapping agencies maintain authoritative basemaps while contractors edit branches. Utilities track asset changes and regulatory approvals. Scientists preserve provenance of derived rasters for reproducibility. Web platforms publish change feeds so downstream systems can incrementally update caches.
FAQ
How does spatial versioning differ from code versioning?
Geometries, topology, and large binary rasters complicate diffs and merges. Conflict resolution may require spatial awareness (e.g., polygon splits) rather than line‑based merges.
What storage models work for long histories without ballooning size?
Delta‑based storage with periodic snapshots, columnar compression, and tiling for rasters balance retrieval speed with cost.
How can reviewers understand what changed between versions?
Generate change maps and human‑readable summaries by feature type and area; link edits to tickets and editor identities for accountability.
When should edits be blocked to maintain topology integrity?
During merges or when dependent datasets (easements, addresses) would be invalidated; use rules to enforce no gaps/overlaps and to update relationships automatically.