`transaction_log` Metricset fetches information about the operation and transaction log of each MSSQL database in the monitored instance. All data is extracted from the https://docs.microsoft.com/en-us/sql/relational-databases/system-dynamic-management-views/database-related-dynamic-management-views-transact-sql?view=sql-server-2017[Database Dynamic Management Views]

* *space_usage.since_last_backup.bytes*: The amount of space used since the last log backup in bytes
* *space_usage.total.bytes*: The size of the log in bytes
* *space_usage.used.bytes*: The occupied size of the log in bytes
* *space_usage.used.pct*: A percentage of the occupied size of the log as a percent of the total log size
* *stats.active_size.bytes*: Total active transaction log size in bytes
* *stats.backup_time*: Last transaction log backup time.
* *stats.recovery_size.bytes*: Log size in bytes since log recovery log sequence number (LSN).
* *stats.since_last_checkpoint.bytes*: Log size in bytes since last checkpoint log sequence number (LSN).
* *stats.total_size.bytes*: Total transaction log size in bytes.
