Should I deploy my C# code to a SQL Server 2005 stored procedure?

benjguin — Wed, 05 Apr 2006 01:29:00 GMT

I think one of the criteria is: Will this make SQL Server cluster consume less resources (CPU, Memory, Network bandwith, ...) to have the C# code inside the database or outside the database?

The reason is that in a typical Web infrastructure where you have a SQL cluster that does not scale out as easily as the other servers (like web servers in the farm), the SQL cluster is the most precious part of the infrastructure.

In a scenario where you have data set operations, like calculating a surface with points stored in the DB, having C# code inside the database is better, because it will cost less to the SQL Server to process calculation inside the DB and not have the whole data transmitted to the Web or calculation Servers.
On the other hand, if you need to do expensive calculations on few data, please do it outside the database.

Another criterion is to avoid having SQL Server connect elsewhere. Typical architectures have most servers connect to SQL Server and SQL Server connect to nearly nothing (just an SMTP server, and maybe some external OLE DB data sources).

SQL Server 2005: Migrate cursor developed stored procedures

benjguin — Tue, 10 May 2005 16:31:00 GMT

In a recent mission, customer had many stored procedures using cursors. Those stored procedures contained business code and it was very important to avoid regressions. So I wondered how Visual Basic .NET stored procedures that could keep business logic would behave compared to pure SQL Statements and cursors.

Here are the results of my tests:

Stored procedure style		Execution time

Transact-SQL cursors		1 minute

Visual Basic .NET,
same logic as cursors		7 s

Transact-SQL, SQL style		< 1 s

I was not surprised to see that SQL style was the fastest, but I also liked the result on VB .NET :-)

Here is the simple code I used

Create a table with 1000 rows. By self joining it, I will get a billion rows.

use misc
go

drop table tableA
go

create table tableA
(
 ID int primary key
)
go

declare @i int;
SET @i=1;
WHILE @i <= 1000
BEGIN
 insert into tableA values(@i);
 SET @i=@i+1;
END
go

select count(*) from tableA
go

VB .NET stored procedure code:

Imports System
Imports System.Data
Imports System.Data.Sql
Imports System.Data.SqlClient
Imports System.Data.SqlTypes
Imports Microsoft.SqlServer.Server


Partial Public Class StoredProcedures
    <Microsoft.SqlServer.Server.SqlProcedure()> _
    Public Shared Sub VBCursor()
        Dim total As SqlTypes.SqlDecimal
        total = 0

        Using cn As New SqlConnection("context connection=true")
            Dim cmd As New SqlCommand( _
                "select cast(a.ID * b.ID as decimal) from tableA a, tableA b", _
                cn)
            cn.Open()
            Dim reader As SqlDataReader
            reader = cmd.ExecuteReader()
            While reader.Read()
                total = total + reader.GetDecimal(0)
            End While
            reader.Close()
            cn.Close()
        End Using

        Dim resultRecord As New _
           SqlDataRecord(New SqlMetaData("result", SqlDbType.Decimal))
        resultRecord.SetDecimal(0, total.Value)
        SqlContext.Pipe.Send(resultRecord)
    End Sub
End Class

Transact-SQL stored procedures code

drop procedure TSQLSet
go

create procedure TSQLSet
as
 select sum(cast(a.ID * b.ID as decimal))
 from tableA a, tableA b
go

drop procedure TSQLCursor;
go


create procedure TSQLCursor
as
 declare @current decimal;
 declare @total decimal;
 set @total=0;

 declare c cursor for 
 select cast(a.ID * b.ID as decimal)
 from tableA a, tableA b;

 open c;

 fetch next from c into @current;
 while @@fetch_status=0
 begin
  set @total = @total + @current;

  fetch next from c into @current;
 end
 close c;
 deallocate c;

 select @total;
go

Test execution code

exec TSQLSet
go

exec TSQLCursor
go

exec VBCursor
go

Benjamin Guinebertière : SQL Server 2005

Should I deploy my C# code to a SQL Server 2005 stored procedure?

SQL Server 2005: Migrate cursor developed stored procedures