Introducing database watcher for Azure SQL

Hi itsmeupa - if you run out of storage capacity on the free ADX cluster, new data won't be collected, but existing data will remain accessible via dashboards. By default, dashboards use the last one hour as the time interval, so after one hour, dashboards will be empty when you open them. You can change the time interval to a time in the past to see the older data.

The free cluster does provide a warning that you are close to running out of space on its management page. At that point you can upgrade to a paid cluster or delete older data by setting a retention policy.

After your watcher has been collecting data for some time, you can check the average amount of data ingested per day for your SQL estate and workload and estimate the retention period that lets you stay under the 100 GB limit. Here's a KQL query to see the original and compressed size of data by table. The 100 GB limit applies to uncompressed data.

// The original and compressed size for each table
.show database extents 
| summarize OriginalSize = format_bytes(sum(OriginalSize)), 
            CompressedSize = format_bytes(sum(CompressedSize))
            by TableName
| order by TableName asc;