Question

I save a big set of data where each record has a time-mark. I wanna save each item also with UTC time-mark so I convert the original time with use of ToUniversalTime() (VB.NET). The use of this method appears to be quite slow. Do you have any tips how to accelerate the process?

For Each i In CollectionOutput.Select(Function(f) f)
    Dim utcTimeMark = i.GetTIMEMARK.ToUniversalTime()
    contextEmanagement.pr_Collection_Store(i.GetID, i.GetTIMEMARK, utcTimeMark, i.GetVALUE)
Next

Where .pr_Collection_Store calls SQL Server stored procedure.

Answer 1

Currently your stored procedure presumably does something like this (I am absolutely guessing at data types here, and I’m assuming you are using SQL Server 2008 or better – please specify your version when asking questions!):

CREATE PROCEDURE dbo.pr_Collection_Store
  @GetID INT,
  @GetTimeMark DATETIME, 
  @UTCTimeMark DATETIME,
  @GetValue INT
AS
BEGIN
  SET NOCOUNT ON;

  INSERT dbo.SomeTable(ID, TimeMark, UTCTimeMark, Value)
    SELECT @GetID, @GetTimeMark, @UTCTimeMark, @GetValue;
END
GO

You could do this instead:

CREATE TYPE dbo.Collection AS TABLE
(
  GetID       INT,
  GetTimeMark DATETIME,
  UTCTimeMark DATETIME,
  GetValue    INT
);
GO

CREATE PROCEDURE dbo.pr_Collection_Store2
  @Collection AS dbo.Collection READONLY
AS
BEGIN
  SET NOCOUNT ON;

  INSERT dbo.SomeTable(ID, TimeMark, UTCTimeMark, Value)
    SELECT GetID, GetTimeMark, UTCTimeMark, GetValue
    FROM @Collection AS c
    WHERE NOT EXISTS (SELECT 1 FROM dbo.SomeTable WHERE ID = c.GetID);
END
GO

Then from the app. Sorry, I know C#, hopefully you can translate this to VB.NET.

DataTable tvp = new DataTable();
tvp.Columns.Add(new DataColumn("i"));
foreach(var i in CollectionOutput)
{ 
    tvp.Rows.Add(i.GetID, i.GetTIMEMARK, i.GetTIMEMARK.ToUniversalTime(), i.GetValue); 
}

using (connection)
{
    SqlCommand cmd = new SqlCommand("dbo.pr_Collection_Store2", connection);
    cmd.CommandType = CommandType.StoredProcedure;
    SqlParameter tvparam = cmd.Parameters.AddWithValue("@Collection", tvp);
    tvparam.SqlDbType = SqlDbType.Structured;
    connection.Open();
    cmd.ExecuteNonQuery();
}