Muokkaa

Jaa

sys.database_query_store_options (Transact-SQL)

  • Artikkeli

Applies to: SQL Server 2016 (13.x) and later versions Azure SQL Database Azure SQL Managed Instance Azure Synapse Analytics SQL database in Microsoft Fabric

Returns the Query Store options for this database.

Column name Data type Description
desired_state smallint Indicates the desired operation mode of Query Store, explicitly set by user.

0 = OFF
1 = READ_ONLY
2 = READ_WRITE
4 = READ_CAPTURE_SECONDARY
desired_state_desc nvarchar(60) Textual description of the desired operation mode of Query Store:

OFF
READ_ONLY
READ_WRITE
READ_CAPTURE_SECONDARY
actual_state smallint Indicates the operation mode of Query Store. In addition to list of desired states required by the user, actual state can be an error state.

0 = OFF
1 = READ_ONLY
2 = READ_WRITE
3 = ERROR
4 = READ_CAPTURE_SECONDARY
actual_state_desc nvarchar(60) Textual description of the actual operation mode of Query Store.

OFF
READ_ONLY
READ_WRITE
ERROR
READ_CAPTURE_SECONDARY

There are situations when actual state is different from the desired state:
- If the database is set to read-only mode, or if Query Store size exceeds its configured quota, Query Store might operate in read-only mode even if you specify read-write.
- In extreme scenarios Query Store can enter an ERROR state because of internal errors. In SQL Server 2017 (14.x) and later versions, if this happens, Query Store can be recovered by executing the sp_query_store_consistency_check stored procedure in the affected database. If running sp_query_store_consistency_check doesn't work, or if you're using SQL Server 2016 (13.x), you need to clear the data by running ALTER DATABASE [YourDatabaseName] SET QUERY_STORE CLEAR ALL;
readonly_reason int When the desired_state_desc is READ_WRITE and the actual_state_desc is READ_ONLY, readonly_reason returns a bit map to indicate why the Query Store is in readonly mode.

1 - database is in read-only mode
2 - database is in single-user mode
4 - database is in emergency mode
8 - database is secondary replica (applies to availability groups and Azure SQL Database geo-replication). This value can be effectively observed only on readable secondary replicas
65536 - the Query Store reached the size limit set by the max_storage_size_mb option. For more information about this option, see ALTER DATABASE SET options.
131072 - The number of different statements in Query Store reached the internal memory limit. Consider removing queries that you don't need or upgrading to a higher service tier to enable transferring Query Store to read-write mode.
262144 - Size of in-memory items waiting to be persisted on disk reached the internal memory limit. Query Store is in read-only mode temporarily until the in-memory items are persisted on disk.
524288 - Database reached disk size limit. Query Store is part of user database, so if there's no more available space for a database, that means that Query Store can't grow further anymore.

To switch the Query Store operations mode back to read-write, see Verify that Query Store collects query data continuously.
current_storage_size_mb bigint Size of Query Store on disk in megabytes.
flush_interval_seconds bigint The period for regular flushing of Query Store data to disk in seconds. Default value is 900 (15 min).

Change by using the ALTER DATABASE <database> SET QUERY_STORE (DATA_FLUSH_INTERVAL_SECONDS = <interval>) statement.
interval_length_minutes bigint The statistics aggregation interval in minutes. Arbitrary values aren't allowed. Use one of the following values: 1, 5, 10, 15, 30, 60, and 1440 minutes. The default value is 60 minutes.
max_storage_size_mb bigint Maximum disk size for the Query Store in megabytes (MB). Default value is 100 MB up to SQL Server 2017 (14.x), and 1 GB in SQL Server 2019 (15.x) and later versions.

For SQL Database Premium edition, the default is 1 GB, and for SQL Database Basic edition, the default is 10 MB.

Change by using the ALTER DATABASE <database> SET QUERY_STORE (MAX_STORAGE_SIZE_MB = <size>) statement.
stale_query_threshold_days bigint Number of days that the information for a query is kept in the Query Store. Default value is 30. Set to 0 to disable the retention policy.
For SQL Database Basic edition, the default is 7 days.

Change by using the ALTER DATABASE <database> SET QUERY_STORE (CLEANUP_POLICY = (STALE_QUERY_THRESHOLD_DAYS = <value>)) statement.
max_plans_per_query bigint Limits the maximum number of stored plans. Default value is 200. If the maximum value is reached, Query Store stops capturing new plans for that query. Setting to 0 removes the limitation for the number of captured plans.

Change by using the ALTER DATABASE<database> SET QUERY_STORE (MAX_PLANS_PER_QUERY = <n>) statement.
query_capture_mode smallint The currently active query capture mode:

1 = ALL - all queries are captured. This is the default configuration value for SQL Server 2016 (13.x) and later versions.

2 = AUTO - capture relevant queries based on execution count and resource consumption. This is the default configuration value for SQL Database.

3 = NONE - stop capturing new queries. Query Store continues to collect compile and runtime statistics for queries that were captured already. Use this configuration cautiously since you might miss capturing important queries.

4 = CUSTOM - Allows more control over the query capture policy using the QUERY_CAPTURE_POLICY options.

Applies to: SQL Server 2019 (15.x) and later versions.
query_capture_mode_desc nvarchar(60) Textual description of the actual capture mode of Query Store:

ALL (default for SQL Server 2016 (13.x) and later versions)

AUTO (default for SQL Database)

NONE

CUSTOM
capture_policy_execution_count int Query capture mode CUSTOM policy option. Defines the number of times a query is executed over the evaluation period. The default is 30.

Applies to: SQL Server 2019 (15.x) and later versions.
capture_policy_total_compile_cpu_time_ms bigint Query capture mode CUSTOM policy option. Defines total elapsed compile CPU time used by a query over the evaluation period. The default is 1000.

Applies to: SQL Server 2019 (15.x) and later versions.
capture_policy_total_execution_cpu_time_ms bigint Query capture mode CUSTOM policy option. Defines total elapsed execution CPU time used by a query over the evaluation period. The default is 100.

Applies to: SQL Server 2019 (15.x) and later versions.
capture_policy_stale_threshold_hours int Query capture mode CUSTOM policy option. Defines the evaluation interval period to determine if a query should be captured. The default is 24 hours.

Applies to: SQL Server 2019 (15.x) and later versions.
size_based_cleanup_mode smallint Controls whether cleanup is automatically activated when total amount of data gets close to maximum size:

0 = OFF - size-based cleanup aren't automatically activated.
1 = AUTO - size-based cleanup is automatically activated when size on disk reaches 90 percent of max_storage_size_mb. This is the default configuration value.

Size-based cleanup removes the least expensive and oldest queries first. It stops when approximately 80 percent of max_storage_size_mb is reached.
size_based_cleanup_mode_desc nvarchar(60) Textual description of the actual size-based cleanup mode of Query Store:

OFF
AUTO (default)
wait_stats_capture_mode smallint Controls whether Query Store performs capture of wait statistics:

0 = OFF
1 = ON

Applies to: SQL Server 2017 (14.x) and later versions.
wait_stats_capture_mode_desc nvarchar(60) Textual description of the actual wait statistics capture mode:

OFF
ON (default)

Applies to: SQL Server 2017 (14.x) and later versions.
actual_state_additional_info nvarchar(4000) Currently unused.

Permissions

Requires the VIEW DATABASE STATE permission.

Remarks

An actual_state_desc value of READ_CAPTURE_SECONDARY is the expected state when Query Store for secondary replicas is enabled. For more information, see Query Store for secondary replicas.

Related content