Tobias Ternstrom Program Mgr., SQL Server Engine Microsoft Corporation DAT 320

Agenda

Passing a set of data to SQL Server Adding MERGE to the equation

Passing a Set of Data to SQL Server

N rows = N executed statements N rows = 1 executed statement

Passing a Set of Data to SQL Server

N rows = N executed statements One client server roundtrip per execution All executions in one batch

Passing a Set of Data to SQL Server

N rows = 1 executed statement Pass the data as a delimited list Pass the data as XML Pass the data as Table Valued Parameter Other options Managed bulk copy to a table Pass data as separate arguments (current limit is 2,100)

Examples

In the examples, we will be passing a set of items to the database for storage Example – “Store the following 1,000 items” Examples we’ll use: Stored Procedures C# & ADO.NET

Pass the Data as a Delimited List

// C# cmd.CommandType = CommandType.StoredProcedure; cmd.CommandText = "Test.spDelimitedString"; cmd.Parameters.AddWithValue("@Values", @"…|…|… …|…|… …|…|…"); cmd.Execute…; -- What happens on the server?

EXEC Test.spDelimitedString @Values = '…|…|… …|…|… …|…|…';

Pass the Data as a Delimited List

To get the best performance, we need to use a SQLCLR Table Valued Function Pros: Performance is good No exposure to SQL Injection Cons: Requires SQLCLR to be enabled on the instance The set of data is not strongly typed Cumbersome implementation Can be simplified by creating one TVF per “list type”

Pass the Data as XML

// C# cmd.CommandType = CommandType.StoredProcedure; cmd.CommandText = "Test.spXML"; cmd.Parameters.AddWithValue("@Values", doc.OuterXml); cmd.Execute…; -- What happens on the server?: EXEC Test.spXML @Values = N'

Pass the Data as XML

Pros Strongly typed (if you use an XML Schema Collection) Performance is OK No exposure to SQL Injection A very good option if your data is already XML!

Great flexibility; remember XML allows for hierarchies Cons Performance is good but not the best Requires knowledge about XML Less cumbersome than the delimited list but still somewhat cumbersome

Pass the Data as a Table Valued Parameter

// C# cmd.CommandType = CommandType.StoredProcedure; cmd.CommandText = "Test.spTVP"; var p = cmd.Parameters.Add("@Values", SqlDbType.Structured); p.TypeName = "Test.OrderTableType"; p.Value = dataTable; cmd.Execute…; -- What happens on the server?: DECLARE @Values Test.OrderTableType; INSERT @Values … EXEC Test.spTVP @Values = @Values;

Pass the Data as Table Valued Parameter

Pros Strongly typed No exposure to SQL Injection Performance is great!

Very easy to use, both on client and server side Cons Less flexible than XML; may require you to pass multiple TVPs where one XML parameter would have been enough Allows for streaming but only to the server

Pass the Data as a Table Valued Parameter



Streaming

// C#

class MyStreamingTvp : IEnumerable { … } … cmd.CommandType = CommandType.StoredProcedure; cmd.CommandText = "Test.spTVP"; var p = cmd.Parameters.Add("@Values", SqlDbType.Structured); p.TypeName = "Test.OrderTableType"; p.Value = new MyStreamingTvp(…); cmd.Execute…;

-- What happens on the server?:

DECLARE @Values Test.OrderTableType; INSERT @Values … EXEC Test.spTVP @Values = @Values;

Pass the Data as a Table Valued Parameter



Streaming

Pros No need for staging the data in memory on the client side Cons Doesn’t stream all the way, stages the data on the server side Requires a type to handle the streaming

A Few More Words on Streaming

If you stream, how “far” do you stream?

N rows = N client server round trips & N proc. executions Streams “all” the way to the destination table Streaming TVP Streams from client to just before the procedure begins execution, i.e., stages the data on the server side The rest Stages the data both on the client and server side Any solution can implement streaming “manually”

What Happens? And What About Performance?

Initial parsing of the data on the server Querying the data Insert the data into a table

1. Initial Parsing on the Server

1. Initial Parsing on the Server

Data passed as delimited string Data passed as XML Data passed as TVP 266 19 32 Execution time (ms., lower is better)

2. Querying the Data

2. Querying the Data

Data passed as delimited string Data passed as XML Data passed as TVP 969 307 33 Execution time (ms., lower is better)

3. Insert the Arguments into a Table

3. Insert the Data into a Table

Data passed as delimited string Data passed as XML Data passed as TVP 1 074 412 88 Execution time (ms., lower is better)

Agenda

Passing a set of data to SQL Server Adding MERGE to the equation

Adding MERGE to the Equation

Also referred to as UPSERT Allows for inserting, updating and deleting data in one statement It is part of ANSI …with one addition!

Adding MERGE to the Equation

Events MATCHED NOT MATCHED NOT MATCHED BY SOURCE Type of event $action

Adding MERGE to the Equation

MERGE Test.Orders AS o USING @Values AS v ON v.OrderId = o.OrderId

WHEN MATCHED THEN UPDATE SET CustomerId = v.CustomerId

,OrderDate = v.OrderDate

,DueDate = v.DueDate

WHEN NOT MATCHED BY SOURCE THEN DELETE WHEN NOT MATCHED THEN INSERT (OrderId, CustomerId, OrderDate) v.OrderDate); VALUES(v.OrderId, v.CustomerId,

Resources

www.microsoft.com/teched Sessions On-Demand & Community www.microsoft.com/learning Microsoft Certification & Training Resources http://microsoft.com/technet Resources for IT Professionals http://microsoft.com/msdn Resources for Developers www.microsoft.com/learning Microsoft Certification and Training Resources

Related Content

DAT313 Inside T-SQL: Enhancements, Techniques, Tips & Tricks DAT305 Best Practices for Exception Handling and Defensive Programming in Microsoft SQL Server DAT04-INT Using the HIERARCHYID Datatype in Microsoft SQL Server 2008 to Maintain and Query Hierarchies 300 - Advanced, Database Platform, Developer Tools, Languages and Frameworks, Hands-on Lab, Middle Tier Platform and Tools

SQL Server Community Resources

The Professional Association for SQL Server (PASS) is an independent, not-for-profit association, dedicated to supporting, educating, and promoting the Microsoft SQL Server community. • • • • Connect: Local Chapters, Special Interest Groups, Online Community Share: PASSPort Social Networking, Community Connection Event Learn: PASS Summit Annual Conference, Technical Articles, Webcasts Become a FREE PASS Member: www.sqlpass.org/RegisterforSQLPASS.aspx

Learn more about the PASS organization www.sqlpass.org/

Additional Community Resources

SQL Server Community Center www.microsoft.com/sqlserver/2008/en/us/community-center.aspx

TechNet Community for IT Professionals http://technet.microsoft.com/en-us/sqlserver/bb671048.aspx

Developer Center http://msdn.microsoft.com/en-us/sqlserver/bb671064.aspx

SQL Server 2008 Learning Portal http://www.microsoft.com/learning/sql/2008/default.mspx

Additional Resources

• • Team Forum: Speaker URL #2 Other: Speaker URL #3 External Resources TVPs http://msdn.microsoft.com/en-us/library/bb510489.aspx

MERGE http://technet.microsoft.com/en us/library/bb510625.aspx

SQL Server 2008 Business Value Calculator:

www.moresqlserver.com

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