sys.resource_stats (Azure SQL Database)

THIS TOPIC APPLIES TO: noSQL Server yesAzure SQL DatabasenoAzure SQL Data Warehouse noParallel Data Warehouse

Returns CPU usage and storage data for an Azure SQL Database. The data is collected and aggregated within five-minute intervals. For each user database, there is one row for every five-minute reporting window in which there is change in resource consumption. This includes CPU usage, storage size change or database SKU modification. Idle databases with no changes may not have rows for every five minute interval. Historical data is retained for approximately 14 days.

The sys.resource_stats view has different definitions depending on the version of the Azure SQL Database Server that the database is associated with. Consider these differences and any modifications your application requires when upgrading to a new server version.

The following table describes the columns available in a v12 server:

Columns (v12 server) Data Type Description
start_time datetime UTC time indicating the start of the 5 minute reporting interval.
end_time datetime UTC time indicating the end of the 5 minute reporting interval.
database_name varchar Name of the user database.
sku varchar Service Tier of the database. The following are the possible values:

Basic

Standard

Premium
storage_in_megabytes float Maximum storage size in megabytes for the time period, including database data, indexes, stored procedures and metadata.
avg_cpu_percent numeric Average compute utilization in percentage of the limit of the service tier.
avg_data_io_percent numeric Average I/O utilization in percentage based on the limit of the service tier.
avg_log_write_percent numeric Average write resource utilization in percentage of the limit of the service tier.
max_worker_percent decimal(5,2) Maximum concurrent workers (requests) in percentage based on the limit of the database’s service tier.

Maximum is currently calculated for the 5 minute interval based on the 15 second samples of concurrent worker counts.
max_session_percent decimal(5,2) Maximum concurrent sessions in percentage based on the limit of the database’s service tier.

Maximum is currently calculated for the 5 minute interval based on the 15 second samples of concurrent session counts.
dtu_limit int Current max database DTU setting for this database during this interval.

Tip

For more context about these limits and service tiers, see the topics Service Tiers and Service tier capabilities and limits.

The following table describes the columns available in a v11 server:

Columns (v11 server) Data Type Description
start_time datetime UTC time indicating the start of the 5 minute reporting interval.
end_time datetime UTC time indicating the end of the 5 minute reporting interval.
database_name nvarchar Name of the database.
sku nvarchar Service Tier of the database. The following are the possible values:

Web

Business

Basic

Standard

Premium
usage_in_seconds int Note: This column is deprecated for v11 and its value is always set to 0.

CPU time used since the last measurement was taken.

For CPU measurement, we recommend that you use the avg_cpu_cores_used column rather than this column.
storage_in_megabytes decimal Maximum storage size in megabytes for the time period, including database data, indexes, stored procedures and metadata.
avg_cpu_cores_used decimal Note: This column is deprecated for v11 and its value is always set to 0.

Average CPU cores used in this interval.
avg_physical_read_iops decimal Note: This column is deprecated for v11 and its value is always set to 0.

Average read IOPS in this interval.
avg_physical_write_iops decimal Note: This column is deprecated for v11 and its value is always set to 0.

Average write IOPS in this interval.
active_memory_used_kb bigint Note: This column is deprecated for v11 and its value is always set to 0.

Count of active memory being used at the end of this interval.
active_session_count int Count of active sessions at the end of this interval.
active_worker_count int Count of active workers at the end of this interval.
avg_cpu_percent decimal Average compute utilization in percentage of the limit of the service tier.
avg_physical_data_read_percent decimal Average I/O utilization in percentage based on the limit of the service tier.
avg_log_write_percent decimal Average write resource utilization in percentage of the limit of the service tier.

Permissions

This view is available to all user roles with permissions to connect to the virtual master database.

Remarks

The data returned by sys.resource_stats is expressed as a percentage of the maximum allowed DTU limits for the service tier/performance level that you are running for Basic, Standard, and Premium databases. For Web and Business tiers, these numbers indicate the percentages in terms of the Standard S2 performance tier. For example, when executing against a Web database, if avg_cpu_percent returns 70%, that indicates 70% of the S2 tier limit. In addition, for Web and Business tiers, the percentages may reflect a number in excess of 100%, which is also based on the S2 tier limit.

When a database is a member of an elastic pool, resource statistics presented as percent values, are expressed as the percent of the max DTU limit for the databases as set in the elastic pool configuration.

For a more granular view of this data, use sys.dm_db_resource_stats dynamic management view in a user database. This view captures data every 15 seconds and maintains historical data for 1 hour. For more information, see sys.dm_db_resource_stats (Azure SQL Database).

Examples

The following example returns all databases that are averaging at least 80% of compute utilization over the last one week.

DECLARE @s datetime;  
DECLARE @e datetime;  
SET @s= DateAdd(d,-7,GetUTCDate());  
SET @e= GETUTCDATE();  
SELECT database_name, AVG(avg_cpu_percent) AS Average_Compute_Utilization   
FROM sys.resource_stats   
WHERE start_time BETWEEN @s AND @e  
GROUP BY database_name  
HAVING AVG(avg_cpu_percent) >= 80  

The following example calculates the average DTU percentage consumption for a given database. (This query only works when run against a v11 server.)

SELECT start_time, end_time,      
  (SELECT Max(v)      
   FROM (VALUES (avg_cpu_percent), (avg_physical_data_read_percent), (avg_log_write_percent)) AS value(v)) AS [avg_DTU_percent]    
FROM sys.resource_stats   
WHERE database_name = '<your db name>'   
ORDER BY end_time DESC;  

See Also

Service Tiers
Service tier capabilities and limits