DBCC FREEPROCCACHE

DBCC FREEPROCCACHE to clear the plan cache carefully. Freeing the plan cache can causes, for example, a stored procedure to be recompiled instead of reused from the cache. This can cause a sudden, temporary decrease in query performance.
DBCC FREEPROCCACHE WITH NO_INFOMSGS;

DBCC SQLPERF(logspace)

DBCC SQLPERF(logspace) is an absolutely functional command if you are only interested in consumption of your database log files. It provides the cumulative size for each log file for each database on the SQL Server instance as well as the amount of space consumed (as a percentage of total log file size). A drawback is the fact that the results are an aggregate for the database.

logspace can be 1 of the value below:
UMSStats - SQL thread management
WaitStats - resources, wait types
IOStats - outstanding reads & writes (note: always zeros)
RAStats - read ahead activity (note: always returns zeros)
Threads - I/O / CPU / memory usage per thread
SpinLockStats - statistics on spinlocks
UMSSpinStats - statistics on UMS
NetStats - ODS statistics
LRUStats - LRU-MRU chain statistics (Note: free page scan always zero)

DBCC SHOWFILESTATS WITH NO_INFOMSGS

This DBCC command provides us the data files for the current database that you select. DBCC SHOWFILESTATS or DBCC SHOWFILESTATS WITH NO_INFOMSGS is the command to display the current database File Name, Database Name, Total Extend, Used Extent, Field ID and File Group.

Get the ID of a Newly Inserted Row Using SCOPE_IDENTITY()

SCOPE_IDENTITY() command will give you the last identity value that was generated in the current scope.

@@Identity will return the last identity value that was generated in the current session but in any scope.

If you database got trigger to insert a new row, @@Identity will give you the id that generated by trigger instead of ID of the last row you inserted.

In order to get the ID of the row that you inserted, which is just what SCOPE_IDENTITY() will give you.

Below is the SQL to get the last inserted ID in the current scope that need to execute together with the commands.

string sqlString = "INSERT INTO Table(Col1, Col2) VALUES (@Col1, @Col2); SELECT SCOPE_IDENTITY () As NewID";
SqlCommand objCmd = new SqlCommand(sqlString, MyConnection);
objCmd.Connection.Open();
objCmd.Parameters.Add(new SqlParameter("@Col1", Col1Value));
objCmd.Parameters.Add(new SqlParameter("@Col2", Col2Value);

SqlDataReader dataReader = objCmd.ExecuteReader();

if (dataReader.HasRows)
{
dataReader.Read();
newRowID = Convert.ToInt32(dataReader["NewID"]);
}

dataReader.Close();

SQL Update Multiple Columns

Below Sql use to update multiple column for a table in 1 shot

*****************

UPDATE Table1
SET (Col1, Col2, Col3, Col4) =
(SELECT Col1a, Col2a, Col3a, Col4a FROM Table2 WHERE Col5a=Table1.Col5)
WHERE Col5 IN (SELECT Col5a FROM Table2 )

*****************

Identity column not getting sequential values

Identity values are not sequential. Even if you do not delete rows, you can end up with missing identity values. If a transaction inserts a new record to the table and ROLLS BACK, you can end up with a missing identity value.

Connect to Sql Server 2005 Express for Window SharePoint Service

If you wanna to connect to the sql server 2005 express after u install window share point to your window server 2003 and when u try to connect to the ServerName\Microsoft##SSEE, it return you error.
Actualy you can't connect to WSS database remotely because network connectivity is disabled by default. ( or without SQL Server Agent Services not installed)

You can use below as ur server name like the image below, it will let you to connect to your share point database

\\.\pipe\mssql$microsoft##ssee\sql\query

The Hibernate Query Language - HQL

NHibernate is equipped with an extremely powerful query language that looks very much like SQL. Hibernate Query Language (HQL) is fully object-oriented, understanding notions like inheritence, polymorphism and association.

The simplest possible Hibernate query is of the form:
- "From Employee" - (similar to SQL "Select * From Employeetbl"
* Employee is a mapping class
if you map the table Employeetbl to a mapping class, so you can use the HQL to select from the mapping file.

Example of Mapping Class for NHibernate
<class table="Employeetbl" name="Employee" lazy="false">
<id type="string" column="Employeeid" name="Employeeid">
<generator class="increment">
</id>
<property type="string" column="EmployeeName" name="EmployeeName"></property>
</class>

NHibernate

NHibernate is a port of Hibernate Core for Java to the .NET Framework. It handles persisting plain .NET objects to and from an underlying relational database. Given an XML description of your entities and relationships, NHibernate automatically generates SQL for loading and storing the objects. Optionally, you can describe your mapping metadata with attributes in your source code.

NHibernate uses the following ways to retrieve objects from the database:

• Hibernate Query Language (HQL)
• Query By Criteria (QBC) and Query BY Example (QBE) using Criteria API
• Native SQL queries
  

NHibernate can work on these Database

• Microsoft SQL Server 2005/2000
• Oracle
• Microsoft Access
• Firebird
• PostgreSQL
• DB2 UDB
• MySQL
• SQLite

NHibernate

SQL Server Express Edition Comparison Table

Express Edition Products for SQL Server Compared
Feature	SQL Server 2005 Express Edition	SQL Server 2005 Express Edition with Advanced Services	SQL Server 2005 Express Edition Toolkit
Database Engine	x	x
Client Components	x	x	x
Full Text Search		x
Reporting Services		x
Management Studio Express		x	x
Business Intelligence Developer Studio			x

Comparation between the SQL Server Database Between:

1. SQL Server 2005 Express Edition

2. SQL Server 2005 Express Edition with Advanced Services

3. SQL Server 2005 Express Edition Toolkit

SQL Server 2005 Management Studio Express

Free to download, free to redistribute, free to embed, and easy for new developers to use immediately, a simple but powerful development environment for building data-driven applications.

The advanced query optimization engine of SQL Server 2005 delivers fast performance with full-text search. Load databases easily through the XCopy feature. Native XML support ensures that your Web environment can easily interoperate with other applications through Web services.

SQL Server 2005 Reporting Services provides a complete, server-based platform for creating, managing, and delivering traditional and interactive reports. Easily create sophisticated reports with tables, charts, and graphics, and then embed them in applications.

Configure SQL Server Express to dynamically tune database parameters to respond to changing usage characteristics. SQL Server Express delivers user updates directly using Microsoft Update, easily plugs in to most enterprise management environments, and supports either silent installs or GUI-based setup and installations.

SQL Server Express Edition

List of DBCC in SQL SERVER 2005

DBCC stands for database consistency checker. We use these commands to check the consistency of the databases.
Example, maintenance, validation task and status checks.

DBCC CHECKALLOC - Check consistency of disk allocation.
DBCC CHECKCATALOG - Check catalog consistency
DBCC CHECKCONSTRAINTS - Check integrity of table constraints.
DBCC CHECKDB - Check allocation, and integrity of all objects.
DBCC CHECKFILEGROUP - Check all tables and indexed views in a filegroup.
DBCC CHECKIDENT - Check identity value for a table.
DBCC CHECKTABLE - Check integrity of a table or indexed view.
DBCC CLEANTABLE - Reclaim space from dropped variable-length columns.
DBCC dllname - Unload a DLL from memory.
DBCC DROPCLEANBUFFERS - Remove all clean buffers from the buffer pool.
DBCC HELP - Help for DBCC commands.
DBCC INPUTBUFFER - Display last statement sent from a client to a database instance.
DBCC OPENTRAN - Display information about recent transactions.
DBCC OUTPUTBUFFER - Display last statement sent from a client to a database instance.
DBCC PROCCACHE - Display information about the procedure cache
DBCC SHOW_STATISTICS - Display the current distribution statistics
DBCC SHRINKDATABASE - Shrink the size of the database data and log files.
DBCC SHRINKFILE - Shrink or empty a database data or log file.
DBCC SQLPERF - Display transaction-log space statistics. Reset wait and latch statistics.
DBCC TRACE - Enable or Disable trace flags
DBCC UPDATEUSAGE - Report and correct page and row count inaccuracies in catalog views
DBCC USEROPTIONS - Return the SET options currently active
DBCC deprecated commands

New Feature in MySQL 6.0

1. The new Falcon transactional storage engine.

2. Support for additional Unicode character sets: utf16, utf32, and 4-byte utf8. These character sets support supplementary Unicode characters; that is, characters outside the Basic Multilingual Plane (BMP).

3. BACKUP DATABASE and RESTORE statements for backup and restore operations.

4. Optimizer enhancements for faster subqueries and joins, including batched index access of table rows for sequences of disjoint ranges by the MyISAM and InnoDB storage engines.

5.The syntax for the LOCK TABLES statement has been extended to support transactional table locks that do not commit transactions automatically. Following LOCK TABLES ... IN SHARE MODE or LOCK TABLES ... IN EXCLUSIVE MODE, you can access tables not mentioned in the LOCK TABLES statement. You can also issue LOCK TABLES statements that acquire transactional locks many times in succession, adding additional tables to the locked set, and without unlocking any tables that were locked previously. When using LOCK TABLES with IN SHARE MODE or IN EXCLUSIVE MODE, tables are not unlocked until the transaction ends.
Transactional locks acquired with LOCK TABLES are released when the transaction ends, either explicitly with COMMIT or ROLLBACK, or implicitly due to a statement that causes implicit commit or because the connection ends.

6. Support for extended comments for tables, columns, and indexes.

More details, visit here http://dev.mysql.com/doc/refman/6.0/en/mysql-nutshell.html

SQLyog

SQLyog GUI is the most powerful MySQL manager and admin tool, combining the features of MySQL Query Browser, Administrator, phpMyAdmin and various other MySQL Front Ends and MySQL clients in a single intuitive interface.

http://www.webyog.com/faq/index.html

LINQ to SQL in C#

This article provides an introduction to employing LINQ to SQL within a Windows Forms application.
Article will address the incorporation of LINQ to SQL into a win forms project, how to use LINQ to SQL to select, insert, update, and delete data, and how to use LINQ to SQL to execute stored procedures.

The article shows some simple examples of LINQ to SQL; from it you can see how easy it is to query against single and related tables and to write filtered queries, execute stored procedures, perform aggregation, and how to insert, update, and delete records from the database.


DataClasses1DataContext dc = new DataClasses1DataContext();
var q =
from a in dc.GetTable()
where a.CustomerID.StartsWith("A")
orderby a.OrderDate ascending
select a;
dataGridView1.DataSource = q;

click here for full article

LINQ tutorials convert a Linq Query resultset to DataTable object

This LINQ tutorials convert a Linq Query resultset to DataTable object.
The tutorials attached with the source code

full article, click here

LINQ Begginer Tutorials

In this tutorial, we looked at the current state of today's data access story. Then we looked at how LINQ and the new language features in C# 3.0 solve these issues by providing us with a consistent set of Standard Query Operators that we can use to query any collection that implements IEnumerable. In this installment, we only focused on in-memory collections of data in order to avoid the confusion that most people have when mixing LINQ with DLinq and XLinq, but rest assured these will be covered in the future installments of this article. Furthermore, because LINQ is just a set of methods that adhere to the naming conventions for the Standard Query Operators, anybody can implement their own LINQ based collections for accessing any other type of data.

More Details, please visit the link

Relational database management system (RDBMS)

A Relational database management system (RDBMS) is a database management system (DBMS) that is based on the relational model as introduced by E. F. Codd. Most popular commercial and open source databases currently in use are based on the relational model.

A short definition of an RDBMS may be a DBMS in which data is stored in the form of tables and the relationship among the data is also stored in the form of tables.

Not be enough virtual memory - SQL Server

For each updated database, SQL Server allocates at least one 64-KB block for use in formatting log records before they are written to disk. This allocation occurs when the first log record is generated for the database, such as during an INSERT, UPDATE, or DELETE statement. Depending on the activity and the size of the generated log records, subsequent modifications might trigger the allocation of additional 64-KB allocations. SQL Server 7.0 will allocate no more than three 54-KB blocks. In SQL Server 2000, the upper number of allocations for each database is a function of the number of processors that SQL Server is configured to use.

Solution
Use the -g startup parameter to leave additional, unreserved virtual memory available for these database allocations. The -g parameter is documented in the Readme.txt of the SQL Server 7.0 service pack, and in SQL Server 2000 Books Online. The "More Information" section in this article includes the settings that Microsoft recommends you use to determine the appropriate value for this setting.

Sql Server 2005 - Twelve Tips For Optimizing Query Performance

1. Turn on the execution plan, and statistics
2. Use Clustered Indexes
3. Use Indexed Views
4. Use Covering Indexes
5. Keep your clustered index small.
6. Avoid cursors
7. Archive old data
8. Partition your data correctly
9. Remove user-defined inline scalar functions
10. Use APPLY
11. Use computed columns
12. Use the correct transaction isolation level

Original Article