If you've ever seen the error message
"The query has been canceled because its estimated cost (X) exceeds the configured X-1 threshold." "Speak with the system administrator."

You might be wondering what a SQL Server query means and how to remedy it when running it. In this essay, I'll look at the source of the problem and how to solve it.

What is the query governor's cost limit?
The query governor cost limit is a SQL Server setting that specifies the maximum time for a query to run. The duration, stated in seconds, is based on an approximation of the query cost for a specific hardware configuration. This setting is intended to prevent persistent queries from consuming too many resources and interfering with the functioning of other queries and applications.

Because the query governor cost limit is set to 3000 by default, any query that is projected to take more than 3000 seconds—or 50 minutes—will be canceled. This value can be changed by the system administrator using the stored function sp_configure.

Why am I getting the error?
If your query has a high expected cost and is too complex or inefficient, you may receive an error warning. The number and size of the tables involved, the indexes and statistics available, the join and aggregation techniques used, the filters and sorting algorithms used, and the SQL Server version and edition all have an impact on how much a query is estimated to cost.

Running a query that entails scanning a large table with no indexes or filters, for example, could result in a high estimated cost. Similarly, performing a query that calls a function or subquery for each row in the return set could result in an extremely high projected cost.

How do I fix the mistake?
The two most likely remedies are to increase the query governor's cost limit or optimize your query. Increase the query governor's cost limit: To increase the query governor cost limit for the active connection, use the SET QUERY_GOVERNOR_COST_LIMIT command. For example, if the estimated cost of the query is 14.000, you may execute the following line before running the query:

SET QUERY_GOVERNOR_COST_LIMIT 15000

Here is an example of how to utilize it:
using Microsoft.Data.SqlClient;
using System.Data;

var connectionString = "Server=YourServerName;Database=YourDatabaseName;User=YourUserName;Password=YourPassword;";

// Create a SqlConnection and SqlCommand
using SqlConnection connection = new SqlConnection(connectionString);

connection.Open();

// Set the QUERY_GOVERNOR_COST_LIMIT before executing the query
var setQueryGovernorCostLimit = "SET QUERY_GOVERNOR_COST_LIMIT 15000;";
using (SqlCommand setQueryGovernorCommand = new SqlCommand(setQueryGovernorCostLimit, connection))
{
setQueryGovernorCommand.ExecuteNonQuery();
}

// Complex SELECT query
var selectQuery = @"
SELECT
    Orders.OrderID,
    Customers.CustomerName,
    Cars.CarModel,
    Colors.ColorName,
    Engines.EngineType,
    Wheels.WheelType,
    Interiors.InteriorType,
    Accessories.AccessoryName,
    Features.FeatureName,
    Options.OptionName,
    -- Add more fields related to the customized automobiles here
FROM
    Orders
    INNER JOIN Customers ON Orders.CustomerID = Customers.CustomerID
    INNER JOIN Cars ON Orders.CarID = Cars.CarID
    INNER JOIN Colors ON Orders.ColorID = Colors.ColorID
    INNER JOIN Engines ON Orders.EngineID = Engines.EngineID
    INNER JOIN Wheels ON Orders.WheelID = Wheels.WheelID
    INNER JOIN Interiors ON Orders.InteriorID = Interiors.InteriorID
    LEFT JOIN OrderAccessories ON Orders.OrderID = OrderAccessories.OrderID
    LEFT JOIN Accessories ON OrderAccessories.AccessoryID = Accessories.AccessoryID
    LEFT JOIN CarFeatures ON Cars.CarID = CarFeatures.CarID
    LEFT JOIN Features ON CarFeatures.FeatureID = Features.FeatureID
    LEFT JOIN CarOptions ON Cars.CarID = CarOptions.CarID
    LEFT JOIN Options ON CarOptions.OptionID = Options.OptionID
WHERE
    -- Your filter conditions for customizations or specific orders here
";


using SqlCommand command = new SqlCommand(selectQuery, connection);

using SqlDataAdapter adapter = new SqlDataAdapter(command);

DataTable dataTable = new DataTable();
adapter.Fill(dataTable);

This will prevent the cancellation of your query. This method is not advised because it can impact the performance of other queries and apps. Additionally, this statement needs to be executed for each connection that requires the query to be done.

• Optimize your query: Reducing the anticipated cost of your query optimization is a preferable course of action. The following methods can help you enhance the efficiency of your queries.
• Use indexes: By reducing the amount of scanning and sorting necessary, indexes can help SQL Server locate the data more quickly. The columns used in your query's join, filter, and order by clauses can all have indexes created on them. The Database Engine Tuning Advisor can also recommend the best indexes for your query.
• Use statistics:  SQL Server can estimate the number of rows and value distribution in tables with statistics. This can assist the SQL Server in selecting the query's optimal execution strategy. The UPDATE STATISTICS statement and the sp_updatestats stored procedure can be used to update the statistics in your tables.
• Simplify your query: You can make your query simpler by eliminating any extraneous tables, joins, filters, columns, or sorting. Your query can be rewritten to take advantage of more effective operators, like EXISTS rather than IN, or it can be divided into shorter searches using temporary tables or common table expressions (CTEs).
• Use the latest SQL Server version and edition: Use the most recent edition and version of SQL Server: These may offer improved performance and optimization features over previous iterations. For instance, the projected cost of your query for SQL Server 2022 Web Edition can be less than that of SQL Server 2019 Web Edition. The @@VERSION function allows you to verify your database's SQL Server version and edition.

The query governor cost limit error is a common problem in SQL Server that occurs when your query exceeds the configured threshold and has a high estimated cost. Increasing the query governor cost limit or optimizing the query are two solutions to this problem. Nonetheless, query optimization is the ideal option because it can improve query performance and efficiency while avoiding potential resource issues.

HostForLIFEASP.NET SQL Server 2022 Hosting