Schema Changes

Schema change detection for monitoring database structural drift

Monitors can track structural changes to your database schemas, alerting you when tables, columns, or types are added, dropped, or altered.

monitor-notification

Schema Change Detection

Schema change detection captures the full column-level state of your database on each monitor run and compares it against the previous state. Any differences — new tables, dropped columns, type changes — are recorded as events.

Configuration

Enable schema change detection with the schemata block:

connection: MY_POSTGRES

schemata:
  enabled: true

objects:
  "public.*":
    metadata: true

Key	Type	Default	Description
enabled	bool	false	Enable schema change detection
exclude	string[]	["*.*_tmp"]	Glob patterns for objects to exclude from schema tracking

Schema change detection requires metadata: true on the monitored objects. Without metadata collection, Sling cannot compare schema states between runs.

Exclude Patterns

Use exclude to skip objects that change frequently or are not relevant:

schemata:
  enabled: true
  exclude:
    - "temp_schema.*"
    - "*.staging_*"
    - "*.*_backup"

When exclude is not set, the default pattern ["*.*_tmp"] excludes temporary tables automatically. Set exclude: [] (empty array) to disable all exclusions.

Detected Events

Event	Description
schema_added	A new schema was detected
schema_dropped	A schema was removed
table_added	A new table or view was detected
table_dropped	A table or view was removed
table_recreated	A table was dropped and re-created
column_added	A new column was added to an existing table
column_dropped	A column was removed from an existing table
column_type_altered	A column's data type was changed

Each event includes the database name, schema name, object name, and object type. For column_type_altered events, both the old and new data types are recorded.

Example

Monitor all tables in multiple schemas for structural changes:

connection: MY_POSTGRES

schemata:
  enabled: true
  exclude:
    - "*.tmp_*"

objects:
  "public.*":
    metadata: true
  "analytics.*":
    metadata: true
  "staging.*":
    metadata: true

Notifications

Enable On Schema Change in your monitor job's notification settings to receive alerts when schema drift is detected.