Monitor Types

This page is the authoritative reference for monitor types in Matia. Types are either auto-generated (freshness and row count per table) or custom (added via Add Monitor). Custom types depend on whether you selected a table or a column and on the column data type.

Auto-Generated Monitors

Enabled per schema in Settings → Account settings → Observability. When you turn a schema on, Matia creates for every table in that schema:

• Freshness: Monitors how long since the table was last updated (or since row count last changed). Alerts when the table goes unusually long without updates.
• Row count: Monitors the number of rows (and optionally byte volume). Alerts on anomalous changes (e.g. sudden drop or spike).

One freshness monitor and one row count monitor per table. Turning the schema off disables these monitors; it does not delete them.

Custom Monitor Types — Any Asset (Table or Column)

• Custom SQL: Tracks the result of a SQL query over time. You choose threshold evaluation method: row count (number of rows returned) or single value (query must return one number). You provide the SQL and can Test before saving. Configure name, channels, anomaly detection, frequency, and optional time window like other custom monitors.

Custom Monitor Types — Column-Level

Available when you select a column in step 1 of Add Monitor:

• Cardinality: Number of distinct values.
• Uniqueness: Percentage of values that are unique.
• Nullness: Percentage of values that are null.

Numeric columns only (in addition to the above):

• Maximum, Minimum, Mean (average), Percent negative, Percent zero, Standard deviation, SUM.

Custom Monitor Types — Table-Level Only

Available when you select a table in step 1:

• Column count: Tracks the number of columns in the table. Alerts when columns are added or removed (schema drift).

For status and lifecycle, see Monitor status and lifecycle. For configuration, see Add a custom monitor and Enable schemas for auto-generated monitors.