dta utility

Applies to: SQL Server

The dta utility is the command prompt version of Database Engine Tuning Advisor. The dta utility is designed to allow you to use Database Engine Tuning Advisor functionality in applications and scripts.

Like Database Engine Tuning Advisor, the dta utility analyzes a workload and recommends physical design structures to improve server performance for that workload. The workload can be a plan cache, a SQL Server Profiler trace file or table, or a Transact-SQL script. Physical design structures include indexes, indexed views, and partitioning. After analyzing a workload, the dta utility produces a recommendation for the physical design of databases and can generate the necessary script to implement the recommendation. Workloads can be specified from the command prompt with the -if or the -it argument. You can also specify an XML input file from the command prompt with the -ix argument. In that case, the workload is specified in the XML input file.

Syntax

dta
[ -? ] |
[
      [ -S server_name [ \instance ] ]
      { { -U login_id [ -P password ] } | -E  }
      { -D database_name [ , ...n ] }
      [ -d database_name ]
      [ -Tl table_list | -Tf table_list_file ]
      { -if workload_file | -it workload_trace_table_name  |
        -ip | -iq }
      { -ssession_name | -IDsession_ID }
      [ -F ]
      [ -of output_script_file_name ]
      [ -or output_xml_report_file_name ]
      [ -ox output_XML_file_name ]
      [ -rl analysis_report_list [ , ...n ] ]
      [ -ix input_XML_file_name ]
      [ -A time_for_tuning_in_minutes ]
      [ -n number_of_events ]
      [ -l time_window_in_hours ]
      [ -m minimum_improvement ]
      [ -fa physical_design_structures_to_add ]
      [ -fi filtered_indexes ]
      [ -fc columnstore_indexes ]
      [ -fp partitioning_strategy ]
      [ -fk keep_existing_option ]
      [ -fx drop_only_mode ]
      [ -B storage_size ]
      [ -c max_key_columns_in_index ]
      [ -C max_columns_in_index ]
      [ -e | -e tuning_log_name ]
      [ -N online_option ]
      [ -q ]
      [ -u ]
      [ -x ]
      [ -a ]
]

Arguments

-?

Displays usage information.

-A time_for_tuning_in_minutes

Specifies the tuning time limit in minutes. dta uses the specified amount of time to tune the workload and generate a script with the recommended physical design changes. By default dta assumes a tuning time of 8 hours. Specifying 0 allows unlimited tuning time. dta might finish tuning the entire workload before the time limit expires. However, to make sure that the entire workload is tuned, we recommend that you specify unlimited tuning time (-A 0).

-a

Tunes workload and applies the recommendation without prompting you.

-B storage_size

Specifies the maximum space in megabytes that can be consumed by the recommended index and partitioning. When multiple databases are tuned, recommendations for all databases are considered for the space calculation. By default, dta assumes the smaller of the following storage sizes:

• Three times the current raw data size, which includes the total size of heaps and clustered indexes on tables in the database.

• The free space on all attached disk drives plus the raw data size.

The default storage size doesn't include nonclustered indexes and indexed views.

-C max_columns_in_index

Specifies the maximum number of columns in indexes that dta proposes. The maximum value is 1024. By default, this argument is set to 16.

-c max_key_columns_in_index

Specifies the maximum number of key columns in indexes that dta proposes. The default value is 16, the maximum value allowed. dta also considers creating indexes with included columns. Indexes recommended with included columns might exceed the number of columns specified in this argument.

-D database_name

Specifies the name of each database that is to be tuned. The first database is the default database. You can specify multiple databases by separating the database names with commas, for example:

dta -D database_name1, database_name2...

Alternatively, you can specify multiple databases by using the -D argument for each database name, for example:

dta -D database_name1 -D database_name2... n

The -D argument is mandatory. If the -d argument hasn't been specified, dta initially connects to the database that is specified with the first USE database_name clause in the workload. If there isn't explicit USE database_name clause in the workload, you must use the -d argument.

For example, if you have a workload that contains no explicit USE database_name clause, and you use the following dta command, a recommendation isn't generated:

dta -D db_name1, db_name2...

But if you use the same workload, and use the following dta command that uses the -d argument, a recommendation is generated:

dta -D db_name1, db_name2 -d db_name1

-d database_name

Specifies the first database to which dta connects when tuning a workload. Only one database can be specified for this argument. For example:

dta -d AdventureWorks2022 ...

If multiple database names are specified, then dta returns an error. The -d argument is optional.

If you're using an XML input file, you can specify the first database to which dta connects by using the DatabaseToConnect element that is located under the TuningOptions element. For more information, see Database Engine Tuning Advisor.

If you're tuning only one database, the -d argument provides functionality that is similar to the -d argument in the sqlcmd utility, but it doesn't execute the USE database_name statement. For more information, see sqlcmd Utility.

-E

Uses a trusted connection instead of requesting a password. Either the -E argument or the -U argument, which specifies a login ID, must be used.

-e tuning_log_name

Specifies the name of the table or file where dta records events that it couldn't tune. The table is created on the server where the tuning is performed.

If a table is used, specify its name in the format: [database_name].[owner_name].table_name. The following table shows the default values for each parameter:

If a file is used, specify .xml as its extension. For example, TuningLog.xml.

-F

Permits dta to overwrite an existing output file. If an output file with the same name already exists and -F isn't specified, dta returns an error. You can use -F with -of, -or, or -ox.

-fa physical_design_structures_to_add

Specifies what types of physical design structures dta should include in the recommendation. The following table lists and describes the values that can be specified for this argument. When no value is specified, dta uses the default -fa IDX.

-fi

Specifies that filtered indexes be considered for new recommendations. For more information, see Create filtered indexes.

-fc

Specifies that columnstore indexes be considered for new recommendations. DTA considers both clustered and nonclustered columnstore indexes. For more information, see Columnstore index recommendations in Database Engine Tuning Advisor (DTA).

Applies to: SQL Server 2016 (13.x) and later versions.

-fk keep_existing_option

Specifies what existing physical design structures dta must retain when generating its recommendation. The following table lists and describes the values that can be specified for this argument:

-fp partitioning_strategy

Specifies whether new physical design structures (indexes and indexed views) that dta proposes should be partitioned, and how they should be partitioned. The following table lists and describes the values that can be specified for this argument:

ALIGNED means that in the recommendation generated by dta every proposed index is partitioned in exactly the same way as the underlying table for which the index is defined. Nonclustered indexes on an indexed view are aligned with the indexed view. Only one value can be specified for this argument. The default is -fp NONE.

-fx drop_only_mode

Specifies that dta only considers dropping existing physical design structures. No new physical design structures are considered. When this option is specified, dta evaluates the usefulness of existing physical design structures and recommends dropping seldom used structures. This argument takes no values. It can't be used with the -fa, -fp, or -fk ALL arguments

-ID session_ID

Specifies a numerical identifier for the tuning session. If not specified, then dta generates an ID number. You can use this identifier to view information for existing tuning sessions. If you don't specify a value for -ID, then a session name must be specified with -s.

-ip

Specifies that the plan cache is used as the workload. The top 1,000 plan cache events for explicitly selected databases are analyzed. This value can be changed using the -n option.

-iq

Specifies that the Query Store is used as the workload. The top 1,000 events from the Query Store for explicitly selected databases are analyzed. This value can be changed using the -n option. For more information, see How Query Store collects data and Tuning Database Using Workload from Query Store with the Database Engine Tuning Advisor.

Applies to: SQL Server 2016 (13.x) and later versions.

-if workload_file

Specifies the path and name of the workload file to use as input for tuning. The file must be in one of these formats: .trc (SQL Server Profiler trace file), .sql (Transact-SQL file), or .log (SQL Server trace file). Either one workload file or one workload table must be specified.

-it workload_trace_table_name

Specifies the name of a table containing the workload trace for tuning. The name is specified in the format: [database_name].[owner_name].table_name.

The following table shows the default values for each:

-ix input_XML_file_name

Specifies the name of the XML file containing dta input information. This must be a valid XML document conforming to DTASchema.xsd. Conflicting arguments specified from the command prompt for tuning options override the corresponding value in this XML file. The only exception is if a user-specified configuration is entered in the evaluate mode in the XML input file. For example, if a configuration is entered in the Configuration element of the XML input file and the EvaluateConfiguration element is also specified as one of the tuning options, the tuning options specified in the XML input file override any tuning options entered from the command prompt.

-k maxtotalindexes

Maximum number of indexes in the recommendation.

-K maxtotalindexes

Maximum number of indexes per table.

-m minimum_improvement

Specifies the minimum percentage of improvement that the recommended configuration must satisfy.

-N online_option

Specifies whether physical design structures are created online. The following table lists and describes the values you can specify for this argument:

If indexes are created online, ONLINE = ON is appended to its object definition.

-n number_of_events

Specifies the number of events in the workload that dta should tune. If this argument is specified and the workload is a trace file that contains duration information, then dta tunes events in decreasing order of duration. This argument is useful to compare two configurations of physical design structures. To compare two configurations, specify the same number of events to be tuned for both configurations and then specify an unlimited tuning time for both also as follows:

dta -n number_of_events -A 0

In this case, it's important to specify an unlimited tuning time (-A 0). Otherwise, Database Engine Tuning Advisor assumes an 8 hour tuning time by default.

-l time_window_in_hours

Specifies the time window (in hours) when a query must have executed for it to be considered by DTA for tuning when using -iq option (Workload from Query Store).

dta -iq -l 48

In this case, DTA uses Query Store as the source of workload and only consider queries that have executed with the past 48 hours.

Applies to: SQL Server 2016 (13.x) and later.

-of output_script_file_name

Specifies that dta writes the recommendation as a Transact-SQL script to the file name and destination specified.

You can use -F with this option. Make sure that the file name is unique, especially if you're also using -or and -ox.

-or output_xml_report_file_name

Specifies that dta writes the recommendation to an output report in XML. If a file name is supplied, then the recommendations are written to that destination. Otherwise, dta uses the session name to generate the file name and writes it to the current directory.

You can use -F with this option. Make sure that the file name is unique, especially if you're also using -of and -ox.

-ox output_XML_file_name

Specifies that dta writes the recommendation as an XML file to the file name and destination supplied. Ensure that Database Engine Tuning Advisor has permissions to write to the destination directory.

You can use -F with this option. Make sure that the file name is unique, especially if you're also using -of and -or.

-P password

Specifies the password for the login ID. If this option isn't used, dta prompts for a password.

-q

Sets quiet mode. No information is written to the console, including progress and header information.

-rl analysis_report_list

Specifies the list of analysis reports to generate. The following table lists the values that can be specified for this argument:

Specify multiple reports by separating the values with commas, for example:

... -rl EVT_FREQ, VIW_TAB, WKLD_ANL ...

-S server_name [ \instance ]

Specifies the name of the computer and instance of SQL Server to connect to. If no server_name is specified, dta connects to the default instance of SQL Server on the local computer. This option is required when connecting to a named instance or when executing dta from a remote computer on the network.

-s session_name

Specifies the name of the tuning session. This is required if -ID isn't specified.

-Tf table_list_file

Specifies the name of a file containing a list of tables to be tuned. Each table listed within the file should begin on a new line. Table names should be qualified with three-part naming, for example, AdventureWorks2022.HumanResources.Department. Optionally, to invoke the table-scaling feature, the name of an existing table can be followed by a number indicating the projected number of rows in the table. Database Engine Tuning Advisor takes into consideration the projected number of rows while tuning or evaluating statements in the workload that reference these tables. There can be one or more spaces between the number_of_rows count and the table_name.

This is the file format for table_list_file:

database_name.[schema_name].table_name [number_of_rows]
database_name.[schema_name].table_name [number_of_rows]
database_name.[schema_name].table_name [number_of_rows]

This argument is an alternative to entering a table list at the command prompt (-Tl). Don't use a table list file (-Tf) if you're using -Tl. If both arguments are used, dta fails and returns an error.

If the -Tf and -Tl arguments are omitted, all user tables in the specified databases are considered for tuning.

-Tl table_list

Specifies at the command prompt a list of tables to be tuned. Place commas between table names to separate them. If only one database is specified with the -D argument, then table names don't need to be qualified with a database name. Otherwise, the fully qualified name in the format: database_name.schema_name.table_name is required for each table.

This argument is an alternative to using a table list file (-Tf). If both -Tl and -Tf are used, dta fails and returns an error.

-U login_id

Specifies the login ID used to connect to SQL Server.

-u

Launches the Database Engine Tuning Advisor GUI. All parameters are treated as the initial settings for the user interface.

-x

Starts tuning session and exits.

Remarks

Press Ctrl+C once to stop the tuning session and generate recommendations based on the analysis dta has completed up to this point. You're prompted to decide whether you want to generate recommendations or not. Press Ctrl+C again to stop the tuning session without generating recommendations.

Examples

A. Tune a workload that includes indexes and indexed views in its recommendation

This example uses a secure connection (-E) to connect to the tpcd1G database on MyServer to analyze a workload and create recommendations. It writes the output to a script file named script.sql. If script.sql already exists, then dta overwrites the file because the -F argument has been specified. The tuning session runs for an unlimited length of time to ensure a complete analysis of the workload (-A 0). The recommendation must provide a minimum improvement of 5% (-m 5). dta should include indexes and indexed views in its final recommendation (-fa IDX_IV).

dta -S MyServer -E -D tpcd1G -if tpcd_22.sql -F -of script.sql -A 0 -m 5 -fa IDX_IV

B. Limit disk use

This example limits the total database size, which includes the raw data and the extra indexes, to 3 gigabytes (GB) (-B 3000) and directs the output to d:\result_dir\script1.sql. It runs for no more than 1 hour (-A 60).

dta -D tpcd1G -if tpcd_22.sql -B 3000 -of "d:\result_dir\script1.sql" -A 60

C. Limit the number of tuned queries

This example limits the number of queries read from the file orders_wkld.sql to a maximum of 10 (-n 10) and runs for 15 minutes (-A 15), whichever comes first. To make sure that all 10 queries are tuned, specify an unlimited tuning time with -A 0. If time is important, specify an appropriate time limit by specifying the number of minutes that are available for tuning with the -A argument as shown in this example.

dta -D orders -if orders_wkld.sql -of script.sql -A 15 -n 10

D. Tune specific tables listed in a file

This example demonstrates the use of table_list_file (the -Tf argument). The contents of the file table_list.txt are as follows:

AdventureWorks2022.Sales.Customer  100000
AdventureWorks2022.Sales.Store
AdventureWorks2022.Production.Product  2000000

The contents of table_list.txt specifies that:

• Only the Customer, Store, and Product tables in the database should be tuned.

• The number of rows in the Customer and Product tables are assumed to be 100,000 and 2,000,000, respectively.

• The number of rows in Store are assumed to be the current number of rows in the table.

  There can be one or more spaces between the number of rows count and the preceding table name in the table_list_file.

  The tuning time is 2 hours (-A 120) and the output is written to an XML file (-ox XMLTune.xml).

dta -D pubs -if pubs_wkld.sql -ox XMLTune.xml -A 120 -Tf table_list.txt

Related content

• SQL command-line utilities (Database Engine)
• Database Engine Tuning Advisor