Monday, December 29, 2008

SQL Native Client

SQL Native Client is the native client side data access library for Microsoft SQL Server, version 2005 onwards. It natively implements support for the SQL Server features including the Tabular Data Stream implementation, support for mirrored SQL Server databases, full support for all data types supported by SQL Server, asynchronous operations, query notifications, encryption support, as well as receiving multiple result sets in a single database session.

SQL Native Client is used under the hood by SQL Server plug-ins for other data access technologies, including ADO or OLE DB. It is also used by the native SQL Server ADO.NET provider, Sql Client. The SQL Native Client can also be directly used, bypassing the generic data access layers.

Monday, December 22, 2008

SQL Server Management Studio

SQL Server Management Studio is a GUI tool included with SQL Server 2005 and later for configuring, managing, and administering all components within Microsoft SQL Server. The tool includes both script editors and graphical tools that work with objects and features of the server. SQL Server Management Studio replaces Enterprise Manager as the primary management interface for Microsoft SQL Server since SQL Server 2005. A version of SQL Server Management Studio is also available for SQL Server Express Edition, for which it is known as SQL Server Management Studio Express (SSMSE).

A central feature of SQL Server Management Studio is the Object Explorer, which allows the user to browse, select, and act upon any of the objects within the server. It can be used to visually observe and analyze query plans and optimize the database performance, among others. SQL Server Management Studio can also be used to create a new database, alter any existing database schema by adding or modifying tables and indexes, or analyze performance. It includes the query windows which provide a GUI based interface to write and execute queries.

Monday, December 15, 2008


Microsoft SQL Server 2005 includes a component named SQL CLR via which it integrates with .NET Framework. Unlike most other applications that use .NET Framework, SQL Server itself hosts the .NET Framework runtime, i.e., memory, threading and resource management requirements of .NET Framework are satisfied by SQLOS itself, rather than the underlying Windows operating system. SQLOS provides deadlock detection and resolution services for .NET code as well. With SQL CLR, stored procedures and triggers can be written in any managed .NET language, including C# and VB.NET. Managed code can also be used to define UDTs which can be persisted in the database. Managed code is compiled to .NET assemblies and after being verified for type safety, registered at the database. After that, they can be invoked like any other procedure. However, only a subset of the Base Class Library is available, when running code under SQL CLR. Most APIs relating to user interface functionality are not available.

When writing code for SQL CLR, data stored in SQL Server databases can be accessed using the ADO.NET APIs like any other managed application that accesses SQL Server data. However, doing that creates a new database session, different from the one in which the code is executing. To avoid this, SQL Server provides some enhancements to the ADO.NET provider that allows the connection to be redirected to the same session which already hosts the running code.

Monday, December 08, 2008

SQL Server 2008

The current version of SQL Server, SQL Server 2008, (code-named "Katmai",)was released (RTM) on August 6th, 2008 and aims to make data management self-tuning, self organizing, and self maintaining with the development of SQL Server Always On technologies, to provide near-zero downtime. SQL Server 2008 will also include support for structured and semi-structured data, including digital media formats for pictures, audio, video and other multimedia data. In current versions, such multimedia data can be stored as BLOBs (binary large objects), but they are generic bit streams. Intrinsic awareness of multimedia data will allow specialized functions to be performed on them. According to Paul Flessner, senior Vice President, Server Applications, Microsoft Corp., SQL Server 2008 can be a data storage backend for different varieties of data: XML, email, time/calendar, file, document, spatial, etc as well as perform search, query, analysis, sharing, and synchronization across all data types.

Other new data types include specialized date and time types and a Spatial data type for location-dependent data. Better support for unstructured and semi-structured data is provided using the FILESTREAM[7] data type has been added, which can be used to reference any file stored on the file system. Structured data and metadata about the file is stored in SQL Server database, whereas the unstructured component is stored in the file system. Such files can be accessed both via Win32 file handling APIs as well as via SQL Server using T-SQL; doing the latter accesses the file data as a binary BLOB. Backing up and restoring the database backs up or restores the referenced files as well. SQL Server 2008 also natively supports hierarchical data, and includes T-SQL constructs to directly deal with them, without using recursive queries

Friday, November 07, 2008

Newborn Screening

Newborn screening tests take place before your newborn leaves the hospital. Babies are tested to identify serious or life-threatening conditions before symptoms begin. Such diseases are usually rare. However, they can affect a baby's normal physical and mental development.
Most tests use a few drops of blood from pricking the baby's heel. A hearing test involves placing a tiny earphone in the baby's ear and measuring his or her response to sound.
If a screening test suggests a problem, your baby's doctor will follow up with further testing. If those tests confirm a problem, the doctor may refer you to a specialist for treatment. Following your doctor's treatment plan can save your baby from lifelong health and developmental problems

Monday, October 20, 2008

Microsoft SQL Server Data storage:Buffer management

SQL Server buffers pages in RAM to reduce disc I/O. Any 8 KB page can be buffered in-memory, and the set of all pages at this time buffered is called the buffer cache. The quantity of memory available to SQL Server decides how lots of page will be cached in memory. The buffer cache is managed by the Buffer Manager. Either analysis from or marks to any side copies it to the buffer cache. Subsequent reads or writes are redirect to the in-memory copy, rather than the on-disc side. The page is updated on the disc by the Buffer Manager only if the in-memory cache has not been referenced for a few times. While writing pages back to disc, asynchronous I/O is use whereby the I/O operation is done in a backdrop thread so that other operation do not have to wait for the I/O operation to total. Each page is written along with its checksum when it is written. When interpretation the page back, its checksum is compute again and matched with the store version to ensure the page has not been injured or tamper with in the mean time.

Monday, October 13, 2008

Microsoft SQL Server :Data storage

The main component of data storage is a database, which is a compilation of tables with typed columns. SQL Server supports different data types, including main types such as Integer, Float, Decimal, Char, Varchar, binary, Text among others. It also allows user-defined composite types to be defined and use. SQL Server also makes server data available as virtual tables and views. A database can also hold other objects including views, stored procedures, index and constraints, in addition to tables, along with a business log. A SQL Server database can contain a utmost of 231 objects, and can span multiple OS-level files with a maximum file size of 220 TB. The data in the database are stored in main data files with an extension .mdf. Secondary data files, identified with an .ndf extension, are used to store elective metadata. Log files are recognized with the .ldf extension.

Sunday, October 05, 2008

Microsoft SQL Server Architecture: Relational engine

The Relational engine equipment the relational data store using the capability provided by SQLOS, which is exposed to this layer via the private SQLOS API. It equipment the type system, to define the types of the data that can be store in the tables, as well as the diverse types of data items that can be stored. It includes the Storage Engine, which handles the way data is stored on constant storage devices and provides methods for fast admission to the data. The storage engine implements log-based business to ensure that any changes to the data are ACID obedient. It also includes the query processor, which is the component that retrieves data. SQL queries specify what data to retrieve, and the query processor optimizes and translates the query into the succession of operations needed to get back the data. The operations are then performing by worker threads, which are scheduled for carrying out by SQLOS.

Monday, September 29, 2008


SQLOS is the base module in the SQL Server architecture. It implements functions normally linked with the Operating System: thread preparation, memory management, I/O management, buffer pool management, resource management, synchronization primitives and locking, and deadlock discovery. Because the requirements of SQL Server are highly dedicated, it equipment its own memory and thread management system, rather than using the generic one implement in the operating system. It divides all the operations it performs into a series of Tasks - both background preservation jobs as well as processing requests from clients. Internally, a pool of employee threads is maintained, onto which the tasks are listed. A task is associated with the thread until it is finished; only after its completion is the thread freed and returns to the pool. If there are no free threads to allocate the task to, the task is temporarily blocked. Each worker thread is map onto either an Operating System thread or a fiber. Fibers are user mode threads that implement co-operative multitasking. Using fibers means SQLOS does all the secretarial of thread organization itself, but then it can optimize them for its particular use. SQLOS also includes synchronization primitives for locking as well as monitoring for the employee threads to detect and recover from deadlocks.

Sunday, September 21, 2008

Microsoft SQL Server

Microsoft SQL Server is a relational database management system (RDBMS) shaped by Microsoft. Its main query language is Transact-SQL, an completion of the ANSI/ISO standard Structured Query Language (SQL) new by both Microsoft and Sybase.


The design of Microsoft SQL Server is broadly divided into three mechanism: SQLOS which implements the basic services necessary by SQL Server, counting thread scheduling, memory administration and I/O management; the Relational Engine, which implements the relational database mechanism including support for databases, tables, queries and stored events as well as implement the type system; and the Protocol Layer which expose the SQL Server functionality.

Monday, September 08, 2008


A laptop computer or notebook computer is a little mobile computer, typically weighing 3 to 12 pounds, although older laptops may weigh up more. Laptops typically run on a single main battery or from an external AC/DC adapter that charge the battery while it also supplies power to the computer itself, even in the event of a power failure. This very potent main battery should not be confused with the much smaller battery nearly all computer use to run the real-time clock and backup BIOS configuration into the CMOS memory when the computer is lacking power.

Laptops contain mechanism that are similar to their desktop counterpart and perform the same functions, but are miniaturized and optimized for mobile use and efficient power expenditure, although typically less controlling for the same price. Laptops usually have liquid crystal display and most of them use different memory module for their random access memory, for instance, SO-DIMM in lieu of the larger DIMMs. In calculation to a built-in keyboard, they may utilize a touchpad or a point stick for input, though an outside keyboard or mouse can usually be attached.

Sunday, August 24, 2008

Bladder Diseases

The bladder is a empty organ in your lower abdomen that food urine. Many situation can affect bladder function. Some ordinary ones are

* Infection - a urinary tract disease in the bladder is also known as cystitis

* Urinary incontinence - loss of bladder control

* Interstitial cystitis - a chronic difficulty in which the bladder wall can turn out to be inflamed and aggravated, leading to frequent, painful urination

* Bladder cancer - the sixth most ordinary cancer in the United States

Doctors diagnose bladder disease using diverse tests. These include urine tests, x-rays and test of the bladder wall with a scope called a cystoscope. Treatment varies depending on the cause of the difficulty. It may comprise medicines and, in harsh cases, surgery.