## TL;DR

Use this when you need to visualize or audit how often schema snapshots occur over time.

## Problem / Use case

You want to track how many schema snapshots are being generated in the system over time to monitor configuration changes or detect unexpected schema churn.

## Query

```dataprime
source system/engine.schema_fields
| groupby snapshotStartTime
    aggregate count() as snapshots
| sortby snapshotStartTime asc
```

This query groups schema field snapshots by their start time, counts how many were recorded per time period, and sorts them chronologically.

## Expected output

| snapshotStartTime   | snapshots |
| ------------------- | --------- |
| 1759957200000000000 | 416940    |
| 1759960800000000000 | 413454    |
| 1759964400000000000 | 408979    |
| 1759968000000000000 | 422913    |

## Variations

- Group by day instead of exact timestamp: `groupby formatTimestamp(snapshotStartTime:timestamp, '%Y-%m-%d') aggregate count() as snapshots`
- Filter by schema type to focus on a specific dataset before grouping.