Querious Help 5

Reading the Results

What the comparison found, object by object.

When the comparison finishes, the window lists every object from both schemas, labeled by what was found. Select an object to see its detail underneath.

For each schema object that changed, you can either view the change itself as its ALTER (usually), or as a diff between its target and reference forms.

The change to a schema object
The change to a schema object
The detailed SQL diff for the schema object
The detailed SQL diff for the schema object

The Four Results #

Result Meaning
Added In the reference but not the target. Synchronizing would create it.
Removed In the target but not the reference. Synchronizing would drop it.
Changed In both, but different. Synchronizing would alter the target's copy.
Identical No differences after applying your options. Hidden by default.

Grouping and Filtering #

The Group By popup arranges the list by:

  • Object Type (Tables, Views, Functions, etc) to review one kind of object at a time.
  • Change Type (Added, Removed, Changed, Identical) to see the shape of the change as a whole, and to check Removed.

Show identical includes objects with no differences. It's off by default because they're the vast majority.

The Detail Pane #

The segmented control chooses what the pane below the list shows for the selected object. Click the selected segment again to hide the pane.

View Shows
Comparison The target's and reference's CREATE statements, so you can read exactly what differs.
Synchronization The SQL that would run against the target for this object. The default.

Recipes #

To review a release before deploying it

  1. Set Reference to staging and Target to production, run the comparison, and group by Change Type.
  2. Read Removed first. Confirm everything there is really meant to be dropped from production.
  3. Read Added, which is what the release introduces.
  4. Go through Changed with the Comparison detail open to see both statements, not just the generated SQL.

To find drift since the last deployment

  1. Compare the environment against the schema it was deployed from.
  2. If the list is full of trivia (definers, auto-increment values, collations), turn those off in the setup and re-run.
  3. What remains is real drift. Objects in Removed were added directly to the live database and never made it into source control.
  4. Copy their CREATE statements from the Comparison pane into a migration before anyone synchronizes them away.

To check one object you already suspect

  1. Check only that object type in the setup.
  2. Turn on Show identical so the object appears whether or not it differs.
  3. Select it and open Comparison to read both definitions.