Schema Diff
Compare PostgreSQL schemas between two connections side by side with tpaw's Atlas-powered diff engine.
Schema Diff lets you compare the schemas of two connected PostgreSQL databases and see exactly what has changed — which tables, enums, indexes, and other objects were added, removed, or modified. The diff is powered by the Atlas schema diff engine and presented as both a high-level summary table and a side-by-side DDL diff in Monaco.
Opening Schema Diff
Schema Diff is available as a dedicated tab view. Open it from the connection's tab bar by selecting Schema Diff. The source connection is pre-filled to the currently active connection.
Note: Schema Diff is currently in Beta.
Configuring the comparison
The configuration panel has two columns — Source and Target — each with:
- Connection — a dropdown showing only currently connected PostgreSQL connections. Disconnected connections are not shown.
- Schema — a text input for the schema name to compare (defaults to
public).
Select a source and target connection, optionally change the schema names, then click Compare to run the diff.
The diff does not run automatically — you must click the Compare button to trigger it explicitly. This prevents unexpected long-running operations when switching tabs.
Reading the results
Summary table
After a successful comparison, the result card shows a summary table with one row per changed object. Each row displays:
| Column | Description |
|---|---|
| Status indicator | + added, − removed, ~ modified |
| Type | The object type (e.g., table, enum, index) |
| Name | The object name |
| Change | A badge showing added, removed, or modified |
Click any row to open a compact DDL diff modal showing just that object's definition on both sides.
Filtering and searching
A chip bar above the table lets you filter by change type:
- All — show every changed object (default)
- + Added — objects that exist in the target but not the source
- − Removed — objects that exist in the source but not the target
- ~ Modified — objects present in both but with different definitions
You can also search by object name or type. Press Cmd+F to focus the search input.
Identical schemas
If no differences are found, tpaw shows a "Schemas are identical" message instead of a summary table.
DDL diff viewer
Per-object diff
Click any row in the summary table to open the DDL diff for that specific object. The modal shows the object's CREATE statement on both sides (source on the left, target on the right) in a side-by-side Monaco DiffEditor with syntax highlighting. Word-wrap is enabled in per-object view.
Full diff
Click View Full Diff in the result card header to open the complete side-by-side diff of all schema DDL. This shows the full sorted DDL for the source and target schemas with all differences highlighted.
Press Escape or click outside the modal to close it.
Migration SQL
When the diff engine is able to generate a migration script, a Migration SQL panel appears at the bottom of the Full Diff modal. This shows the SQL statements needed to migrate the source schema to match the target.
Click Open in Query Tab (in the result card) to load the migration SQL directly into a new query editor tab for review or execution.