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Getting started

Install Parallax, connect to two databases and run your first comparison.

Parallax compares two databases, writes the SQL to make one match the other, and deploys it. It works with PostgreSQL, SQL Server and MySQL, for the schema and for the data in the tables.

Database Versions tested
PostgreSQL 13, 16, 17
SQL Server 2019, 2022
MySQL 8.0, 8.4

Install

Get Parallax from the Microsoft Store. It runs on Windows 10 and 11, 64-bit. The Store installs new versions on its own; see Troubleshooting.

When Parallax starts, it shows “Starting the comparison engine…” while its engine starts. If the engine does not start, see Troubleshooting.

The Overview page

Parallax opens on Overview. It shows:

  • New comparison and Add connection buttons.

  • The Get started checklist, with “<n> of 4 done” and the next step’s button:

    1. Add connection
    2. Create project
    3. Run a comparison
    4. Open a comparison

    The checklist hides once all four steps are done.

  • Tiles with the number of Connections, Projects, Comparisons and Deployments. Choose a tile to open its page.

  • Recent comparisons and Recent deployments, six of each, newest first. Choose All to see the full list.

Try the sample project

To see Parallax at work before connecting your own databases:

  1. Open Projects.
  2. Choose Sample.
  3. On the new Shop sample project, choose Compare.

The sample compares a development and a production copy of a small shop database. It is safe to experiment with. Deleting the sample project also removes its sample connections.

Your first comparison

  1. Add your connections. Open Connections, choose New connection, and enter the engine, host, port and the account to sign in with. Choose Test connection, then Add connection. See Connections.

  2. Create a project. Open Projects and choose New project. Pick the source (X): the database with the changes you want, often a development or release database. Pick the target (Y): the database to update, like production. Choose Create project. See Projects and options.

  3. Compare. Choose Compare on the project, or double-click it. When the comparison finishes, its result opens.

  4. Read the result. The result lists every object that is:

    • Different: on both sides, with different definitions
    • Only in source: deploying creates it in the target
    • Only in target: deploying drops it from the target
    • Identical: the same on both sides

    Select an object to see its two definitions side by side, or its change script. See Reading a comparison.

  5. Deploy. Choose Deploy, pick the differences to deploy, review the SQL, and run it. See How deployments work.

The sidebar

Group Section What it holds
Workspace Overview Getting started and recent activity
Connections The database servers Parallax can reach
Schema Projects Pairs of databases to compare
Comparisons Results of schema comparisons
Deployments Changes applied to databases
ERDs Entity-relationship diagrams of a database, to view here or in Lucidchart
More Data compare Compare the rows in two databases
Pipelines Compare a chain of environments, e.g. dev → staging → prod
Snapshots Saved copies of a database’s schema

Each section shows how many items it holds. The footer shows the engine’s status, and buttons for Diagnostics, the light or dark theme, and collapsing the sidebar to icons. In a narrow window, the sidebar shows as icons.

While a comparison, deployment or other long job runs, a banner at the top shows its progress on every page.

The File menu has New connection… and New project…. The View menu has Toggle light/dark theme (Ctrl+Shift+L) and Reload (Ctrl+R). The Help menu has Diagnostics…, Check for updates…, Open log folder and Toggle verbose logging.

What next

NextConnections