Func<T,TResults> – Flexible delegate to create reusable functions

Today while googling i found an interesting feature of delegate Func<T,TResults> ,it allows us to represent a method that can be passed as a parameter without declaring a custom delegate explicitly and the method must have one parameter that is passed to it by value and must return a value.

In the following example we need to explicitly define a new delegate and assign a named method to it.

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
namespace BlogSamples
{
    delegate int ConvertMethod(int _x);
    class Program
    {
        static void Main(string[] args)
        {
            ConvertMethod objConv = SquareMe;
            int val = 5;
            //delegate is called
            Console.WriteLine(objConv(val));
            Console.ReadKey();
        }
        private static int SquareMe(int myInt)
        {
            return myInt * myInt;
        }
    }
}

Without explicitly defining a new delegate it can be simplified as below

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
namespace BlogSamples
{
    class Program
    {
        static void Main(string[] args)
        {
            Func convertMethod = SquareMe;
            int val = 6;
            Console.WriteLine(convertMethod(val));
            Console.ReadKey();
        }
        private static int SquareMe(int myInt)
        {
            return myInt * myInt;
        }
    }
}

Please see the msdn link for more references.

Restoring backup of Partitioned Database in sql server 2008

If we need to restore a database having some 'n' number of partition its very tedious to give all the partitioned filegroup to restore into a particular location in the database server.The below example we demonstrate to perform the task.Run the script in the master database.

IF Exists (SELECT '1' from sysobjects where name = 'RESTOREBKP_2008' and type ='p')
BEGIN
DROP PROCEDURE dbo.RESTOREBKP_2008
END
GO
CREATE PROCEDURE RESTOREBKP_2008
(
@DBName varchar(max), -- DATABASENAME
@BackupPath varchar(max), -- BACKUPFILEPATH
@Path varchar(max) -- PHYSICALPATH
)
AS
BEGIN

DECLARE
--Variables declaration
@ResFilesOnly Nvarchar(max),
@ResQuery Nvarchar(max),
@STR AS nVARCHAR(MAX),
@Logicalname as nvarchar(max),
@physicalname as nvarchar(max)

--- LOOP Variable
DECLARE @I AS INT, @J AS INT


set @ResFilesOnly='RESTORE FILELISTONLY
FROM DISK = '''@BackupPath''''

set @I = 1

DECLARE @RESTORE AS TABLE(
LogicalName nvarchar(128), PhysicalName nvarchar(500), Type char(1), FileGroupName nvarchar(128),
Size numeric(20,0), MaxSize numeric(38,0), FileID bigint, CreateLSN numeric(38,0),
DropLSN numeric(25,0) NULL, UniqueID uniqueidentifier, ReadOnlyLSN numeric(25,0) NULL,
ReadWriteLSN numeric(25,0) NULL, BackupSizeInBytes bigint, SourceBlockSize int,
FileGroupID int, LogGroupGUID uniqueidentifier NULL, DifferentialBaseLSN numeric(38,0) NULL,
DifferentialBaseGUID uniqueidentifier, IsReadOnly bit, IsPresent bit,TDEThumbprint varchar(500)
)
INSERT INTO @RESTORE
EXEC sp_executesql @ResFilesOnly

SELECT @J = MAX(FILEID) FROM @RESTORE
SET @STR = ''
WHILE @I <= @J
BEGIN
SELECT
@Logicalname = LTRIM(RTRIM(Logicalname)), @physicalname = LTRIM(RTRIM(REVERSE(LEFT(REVERSE(physicalname),CHARINDEX('\',REVERSE(physicalname))-1))))
FROM
@RESTORE
WHERE
FILEID = @I
SET @STR = @STR + 'MOVE N''' + @Logicalname + ''' TO N''' + @Path + @physicalname + ''', '

SET @I = @I + 1
END

--Restore Backup Query
set @ResQuery = 'RESTORE DATABASE ' + @dbname + ' FROM DISK = '''+ @BackupPath + ''' WITH '+ @STR +
N' NOUNLOAD, STATS = 10'

EXECUTE SP_EXECUTESQL @ResQuery
END

Execute this Stored Procedure in your master database as given below

EXEC RESTOREBKP_2008 '', '', ''

Note:-In case of any clarification please mail me to mail@renjucool.com

See this article in MSDN by me http://code.msdn.microsoft.com/Sql2008PartionedDb

Sql Server Reporting Service –Silverlight enabled

For sometime before i’m thinking of the reports(SSRS/CR) to be enabled by silverlight technologies, so after googling i found out a amazing tool from perpetuumsoft to display SSRS reports in RIA enabled UI can do a deep zoom!!!!.Seems rocking!!!!

Debugging for Silverlight

Find out the RIA platform silverlight debugging tool from MSFT,whdc. also see this blog regarding the memory leak problem in silverlight.

 http://blogs.msdn.com/delay/archive/2009/03/11/where-s-your-leak-at-using-windbg-sos-and-gcroot-to-diagnose-a-net-memory-leak.aspx

Table Comparison in Sql Server

SQL Server is having a command line tool (TableDiff) to compare the data in two tables.It will perform the following task.

1. A row by row comparison between a source table in an instance of Microsoft SQL Server acting as a replication Publisher and the destination table at one or more instances of SQL Server acting as replication Subscribers.
   
2. Perform a fast comparison by only comparing row counts and schema.
   
3. Perform column-level comparisons.
   
4. Generate a Transact-SQL script to fix discrepancies at the destination server to bring the source and destination tables into convergence.
   
5. Log results to an output file or into a table in the destination database.

eg:

 

 "C:\Program Files\Microsoft SQL Server\90\COM\TableDiff.exe" -sourceserver "SERVERNAME" -sourcedatabase "DBNAME" -sourceschema "dbo" -sourcetable "SOURCETABLE1" -sourceuser "sa" -sourcepassword "PASSWORD" -destinationserver "SERVERNAME" -destinationdatabase "DBNAME" -destinationschema "dbo" -destinationtable "SOURCETABLE2" -destinationuser "sa" -destinationpassword "PASSWORD" -dt -o "C:\Documents and Settings\renjuraj\My Documents\diff.xls"

 

Run the above command in command prompt.Please refer your sql server installation path(C:\Program Files\Microsoft SQL Server\90\COM\TableDiff.exe).

Windows 7 Startup Animation Design

View Full Album

Rolf Ebeling, a senior user experience lead for the User Experience Design and Research Team for Windows, Windows Live, and Internet Explorer, is the man who designed the 105-frame Windows 7 boot animation that millions see or will see every day for years to come. Along with developing the famous boot animation, he also helped with the appearance and functionality of the calculator. He's already confirmed that he'll be working on the next version of Windows. Ebeling was only with the company for four months before he was asked to start designing what would become four swirling balls of light that come together to form a pulsing Windows 7 flag. Although the sketches of the early boot animation concept pictured above don't show it, Ebeling said he looked everywhere for inspiration, including street lights in the rain, light reflecting off water, and fireflies. A self-taught designer with a degree in English literature, Ebeling was a creative director for Newsweek.com in New York before joining Microsoft in April 2008, his first software job.

Source :Microsoft

Longest Running Procedures in Sql Server

Its useful to determine which SProc/Code have the greatest impact on the Server. Sometimes, that is determined by examining the I/O cost,sometimes by the Exectution Duration. In this eg, Total Impact is determined by examining the length of execution and the frequency of execution.

SELECT TOP 10 
 temp.text as ProcedureName, 
 s.execution_count as ExecutionCount, 
 isnull( s.total_elapsed_time / s.execution_count, 0 ) as AvgExecutionTime, 
 s.total_worker_time / s.execution_count as AvgWorkerTime, 
 s.total_worker_time as TotalWorkerTime, 
 s.max_logical_reads as MaxLogicalReads, 
 s.max_logical_writes as MaxLogicalWrites, 
 s.creation_time as CreationDateTime, 
 s.total_physical_reads as PhysicalReads,
 isnull( s.execution_count / datediff( second, s.creation_time,getdate()), 0 )as CallsPerSecond
FROM sys.dm_exec_query_stats s 
CROSS APPLY sys.dm_exec_sql_text( s.sql_handle ) temp 
ORDER BY 
-- s.total_elapsed_time DESC 
s.execution_count desc

Transaction Log growing in Sql Server

Transaction log in SQL Server is one of the most important parts of a SQL Server , as well as one of the most common generators of problems I see online.The following are the causes for transaction log growth,

 

1.Due to Uncommitted transactions. We can find if there are any open transactions using DBCC OPENTRAN.
2.Running DBCC REINDEX, CREATE INDEX operations with the database in Full Recovery model.
3.Running extremely large transactions like Bulk Insert, Select Into commands.
http://support.microsoft.com/kb/317375/

 

The following are the proactive measures in order to minimize the unexpected log file growth,

 

1.If you do not want point in time recovery of your databases then you can change the recovery model to Simple.
2.Set the size of the transaction log files to a large value to avoid the automatic expansion of the transaction log files.
3.Configure the automatic expansion of transaction log in terms of MB instead of %.
4.Backup the transaction log regularly to delete the inactive transactions in your transaction log if you are using full or bulk logged recovery model.
5.You can switch the recovery model to Bulk logged from full recovery model if you perform some bulk inserts, select into, bcp, alter index, create index commands because these operations will be minimally logged in bulk logged recovery model and after those operations are completed you can switch over to full recovery model.

 

Solutions

1. Take full backup of your database
2. Take t-log backup of your database frequently say every 30 or 15 minutes so that log file will not grow drastically
3. Shrink if you do not have any free space. You can perform this operation manually if required.
4. Generally avoid shrinking the database and keep it as the last option.

If you are in full recovery, then no it won't be truncated.run the following command:

 

SELECT DATABASEPROPERTYEX('Lorenzo347', 'RECOVERY')

If it returns FULL or BULK_LOGGED, then you will have to backup the log, either to disk or specifying the truncate only to get it truncate the space off.  If you do that, then you might as well change your recovery model to SIMPLE and be done with this problem.  If it says you are already in SIMPLE, then it should shrink without problem.

 

backup log <your database name> with truncate_only

 

Shrink Log files

 

DECLARE @LogFileName varchar(100)

SELECT @LogFileName = rtrim(name)

FROM dbo.sysfiles

WHERE Name like '%_log%'

dbcc SHRINKFILE(@LogFileName, 2)

Shrinks the log file  to 2 MB

http://msdn.microsoft.com/en-us/library/aa258824(SQL.80).aspx

Note:Detaching and deleting the log is definitely not advisable   At best it forces you to take your database offline. Worst case is that you invalidate your entire database and have to  restore from backup.

 

Index to be recreated in Sql Server

When your database grows, the index fragmentation becomes too high,that will scale down the performance of the sql server. To overcome that we need to re-build the index, that should be done at the down time of the server.Here there is a query that will list all the index to be recreated/rebuild.It uses the following tables(sys.indexes,sys.tables,sys.schemas,sys.dm_db_index_physical_stats,sys.partitions). For detailed checkup change the last NULL in the dm_db_index_physical_stats call to 'SAMPLED' or even 'DETAILED'

SELECT 'ALTER INDEX [' + ix.name + '] ON [' + s.name + '].[' + t.name +'] ' +
CASE WHEN ps.avg_fragmentation_in_percent > 40 THEN 'REBUILD'
ELSE 'REORGANIZE' END +
CASE WHEN pc.partition_count > 1 THEN ' PARTITION = ' +
cast(ps.partition_number as nvarchar(max)) ELSE '' END
FROM sys.indexes AS ix INNER JOIN sys.tables t
ON t.object_id = ix.object_id
INNER JOIN sys.schemas s
ON t.schema_id = s.schema_id
INNER JOIN (SELECT object_id, index_id,avg_fragmentation_in_percent, partition_number
FROM sys.dm_db_index_physical_stats (DB_ID(), NULL,NULL, NULL, NULL)) ps
ON t.object_id = ps.object_id AND ix.index_id = ps.index_id
INNER JOIN (SELECT object_id, index_id, COUNT(DISTINCT
partition_number) AS partition_count
FROM sys.partitions
GROUP BY object_id, index_id) pc
ON t.object_id = pc.object_id AND ix.index_id = pc.index_id
WHERE ps.avg_fragmentation_in_percent > 10 AND
ix.name IS NOT NULL

VS 2010 Tranining kit

MSFT released the training kit(october preview) of VS 2010 framework.Can download it from Microsoft website.The Beta 2 release of the Training Kit contains 15 presentations, 19 hands-on labs, and 13 demos. Many technologies are covered in this release, including: C# 4, VB 10, F#, Parallel Extensions, Windows Communication Foundation, Windows Workflow, Windows Presentation Foundation, ASP.NET 4, Entity Framework, ADO.NET Data Services, Managed Extensibility Framework, and Visual Studio Ultim

Click here to dowload from Microsoft