# Automatic Sync Configuration Update

### **Overview**

Schema Updates Propagation keeps your sync running as source schemas evolve. You control whether new tables/columns are auto-added and whether deleted tables/columns are automatically removed from the sync mapping. This prevents sync pauses and reduces manual maintenance.

### **I. Schema Change Detection Frequency (Per App)**

* **Enable schema updates**: turns detection on/off for that app.
* **Frequency**: how often Stacksync checks for schema changes (1 hour to 24 hours).
* **Propagate now**: triggers an immediate detection run for that app. Useful when you just made a schema change in an app and want it to be propagated right now.

Notes:

* Detection can occur sooner if schema changes are observed during normal sync runs. This will enable the sync to keep running while otherwise the sync would pause in case a column or table it needs to sync does not exist anymore.

<figure><img src="https://2867423571-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FfJjIdV9cuW6K8asJjTPJ%2Fuploads%2FxGVQ6aSflFWfeyZTKXuq%2FScreen%20Shot%202026-02-12%20at%205.52.58%20PM.png?alt=media&#x26;token=ef227987-8277-4cc2-a0ab-0389b3d8408b" alt=""><figcaption></figcaption></figure>

### **II. When New Tables Are Detected**

In **When the schema of tables already in sync is updated**, configure column-level behavior per table:

* **Do not propagate**: new tables are ignored (recommended if you manage schemas via migrations).
* **Auto-create in target**: new tables detected in the source are created in the target and added to the sync.

You can also add exclusions:

* **Exclude table names** by exact name.
* **Exclude by regex** for patterns (e.g., `^temp_.*`).

Notes:

* Auto-creation is only available if the target system supports creating tables and if the necessary permissions have been set to the user / service account granted access to Stacksync.

<figure><img src="https://2867423571-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FfJjIdV9cuW6K8asJjTPJ%2Fuploads%2F0QSkulFa5d3ZHgg8ipdW%2FScreen%20Shot%202026-02-12%20at%205.56.51%20PM.png?alt=media&#x26;token=233d0c43-b9e0-4bc8-b2ae-a19c86c43add" alt=""><figcaption></figcaption></figure>

### **III. When Existing Tables Change (Columns)**

In **When the schema of tables already in sync is updated**, configure column-level behavior per table:

* **Add New Columns**: if enabled, a newly detected column in the source is created in the target and added to the sync.
* **Unsync Deleted Columns**: if enabled, deleted source columns are removed from the sync mapping.

<figure><img src="https://2867423571-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FfJjIdV9cuW6K8asJjTPJ%2Fuploads%2FIjoyxD8h6xW6jKLMZYw4%2FScreen%20Shot%202026-02-12%20at%205.59.56%20PM.png?alt=media&#x26;token=a97e73dd-4e09-4e2a-9dff-3ba6f06064ae" alt=""><figcaption></figcaption></figure>

Additional controls by clicking on the gear icon:

* **Column exclusions**: per table, exclude columns by exact name or regex.
* **Default behavior for new tables’ fields**: a default row sets how columns should be handled for tables added later.

<figure><img src="https://2867423571-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FfJjIdV9cuW6K8asJjTPJ%2Fuploads%2FYHqphE6GcEFu7s1HIUN0%2FScreen%20Shot%202026-02-12%20at%206.01.04%20PM.png?alt=media&#x26;token=0b05bba0-c735-450a-b661-26a3d2dec146" alt=""><figcaption></figcaption></figure>

Important:

* Removing a column from the sync does **not** delete the column in the target app; it simply stops syncing it.

#### **Column Renames (Automatic Mapping)**

When a column is renamed in the source app, Stacksync attempts to preserve the sync by matching the column using the app’s immutable field identifiers (when available). This means a rename is treated as the same column with a new name, not as a deletion plus a new column.

What this does:

* Keeps the sync running without manual remapping.
* Avoids creating duplicate columns when only the name changed.
* Applies to apps that expose stable, immutable field IDs.

Notes:

* If the app does not provide immutable field IDs, a rename may be interpreted as “deleted + new” and will follow your column add/remove rules.

### **IV. When Tables Are Deleted**

In **When tables are deleted in an app**, choose the behavior:

* **Auto-unsync deleted tables** (recommended): removes the table from the sync mapping and keeps the sync running.
* **Keep in mapping**: the sync pauses and notifications are sent to workspace collaborators.

Important:

* Auto-unsync does **not** delete the target table in the app. It only stops syncing it.

<figure><img src="https://2867423571-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FfJjIdV9cuW6K8asJjTPJ%2Fuploads%2FIHgYxVUMt3NytXXAuPNM%2FScreen%20Shot%202026-02-12%20at%206.02.13%20PM.png?alt=media&#x26;token=ac81feb4-0dbc-41b7-aedd-29b0b62fb93e" alt=""><figcaption></figcaption></figure>

If you have any questions, feel free to reach out at *<hello@stacksync.com>*, we are happy to help!