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The database server uses a B-tree structure to organize index information. B-Tree generally has following types of index PAGES or NODES:
• ROOT node: A root node contains node pointers to branch nodes which can be only one.
• branch nodes: A branch node contains pointers to leaf nodes or other branch nodes which can be two or more.
• leaf nodes: A leaf node contains index ITEMS and horizontal pointers to other leaf nodes which can be many.

The database server uses a B-tree structure to organize index information. B-Tree generally has following types of index pages or nodes:
• root node: A root node contains node pointers to branch nodes which can be only one.
• branch nodes: A branch node contains pointers to leaf nodes or other branch nodes which can be two or more.
• leaf nodes: A leaf node contains index items and horizontal pointers to other leaf nodes which can be many.

UNION
The UNION command is used to SELECT related information from two tables, much LIKE the JOIN command. However, when using the UNION command all selected columns need to be of the same data type. With UNION, only distinct values are selected.

UNION ALL
The UNION ALL command is equal to the UNION command, except that UNION ALL selects all values.
The difference between Union and Union all is that Union all will not eliminate duplicate ROWS, instead it just pulls all rows from all tables fitting your QUERY SPECIFICS and combines them into a table.

UNION
The UNION command is used to select related information from two tables, much like the JOIN command. However, when using the UNION command all selected columns need to be of the same data type. With UNION, only distinct values are selected.

UNION ALL
The UNION ALL command is equal to the UNION command, except that UNION ALL selects all values.
The difference between Union and Union all is that Union all will not eliminate duplicate rows, instead it just pulls all rows from all tables fitting your query specifics and combines them into a table.

ROW_NUMBER() returns a COLUMN as an expression that contains the row’s number within the result set. This is only a number USED in the context of the result set, if the result CHANGES, the ROW_NUMBER() will CHANGE.

ROW_NUMBER() returns a column as an expression that contains the row’s number within the result set. This is only a number used in the context of the result set, if the result changes, the ROW_NUMBER() will change.

TABLESAMPLE allows you to extract a sampling of rows from a table in the FROM CLAUSE. The rows retrieved are random and they are not in any order. This sampling can be based on a PERCENTAGE of number of rows. You can use TABLESAMPLE when only a sampling of rows is necessary for the APPLICATION instead of a FULL result set.

TABLESAMPLE allows you to extract a sampling of rows from a table in the FROM clause. The rows retrieved are random and they are not in any order. This sampling can be based on a percentage of number of rows. You can use TABLESAMPLE when only a sampling of rows is necessary for the application instead of a full result set.

Aggregate functions perform a calculation on a set of values and RETURN a single value. Aggregate functions ignore NULL values except COUNT function. HAVING clause is used, along with GROUP BY, for FILTERING query using aggregate values.
FOLLOWING functions are aggregate functions.
AVG, MIN, CHECKSUM_AGG, SUM, COUNT, STDEV, COUNT_BIG, STDEVP, GROUPING, VAR, MAX, VARP

Aggregate functions perform a calculation on a set of values and return a single value. Aggregate functions ignore NULL values except COUNT function. HAVING clause is used, along with GROUP BY, for filtering query using aggregate values.
Following functions are aggregate functions.
AVG, MIN, CHECKSUM_AGG, SUM, COUNT, STDEV, COUNT_BIG, STDEVP, GROUPING, VAR, MAX, VARP

sqlcmd is enhanced version of the ISQL and osql and it provides way more FUNCTIONALITY than other TWO options. In other words sqlcmd is better replacement of isql (which will be deprecated EVENTUALLY) and osql (not INCLUDED in SQL Server 2005 RTM). sqlcmd can work two modes –

• BATCH 
• interactive modes.

sqlcmd is enhanced version of the isql and osql and it provides way more functionality than other two options. In other words sqlcmd is better replacement of isql (which will be deprecated eventually) and osql (not included in SQL Server 2005 RTM). sqlcmd can work two modes –

A dirty read occurs when two operations say, read and write occurs together giving the incorrect or unedited data. Suppose, A has changed a row, but has not COMMITTED the CHANGES. B reads the uncommitted data but his view of the data may be WRONG so that is Dirty Read.

A dirty read occurs when two operations say, read and write occurs together giving the incorrect or unedited data. Suppose, A has changed a row, but has not committed the changes. B reads the uncommitted data but his view of the data may be wrong so that is Dirty Read.

Filestream allows you to store large objects in the file system and have these files integrated within the database. It enables SQL SERVER based APPLICATIONS to store unstructured data such as DOCUMENTS, images, audios, videos ETC. in the file system. FILESTREAM BASICALLY integrates the SQL Server Database Engine with New Technology File System (NTFS); it basically stores the data in varbinary (max) data type. Using this data type, the unstructured data is stored in the NTFS file system and the SQL Server Database Engine manages the link between the Filestream column and the actual file located in the NTFS. Using Transact SQL statements users can insert, update, delete and select the data stored in FILESTREAM enabled tables.

Filestream allows you to store large objects in the file system and have these files integrated within the database. It enables SQL Server based applications to store unstructured data such as documents, images, audios, videos etc. in the file system. FILESTREAM basically integrates the SQL Server Database Engine with New Technology File System (NTFS); it basically stores the data in varbinary (max) data type. Using this data type, the unstructured data is stored in the NTFS file system and the SQL Server Database Engine manages the link between the Filestream column and the actual file located in the NTFS. Using Transact SQL statements users can insert, update, delete and select the data stored in FILESTREAM enabled tables.

A Pivot Table can AUTOMATICALLY sort, count, and total the data STORED in one table or spreadsheet and create a second table displaying the summarized data. The PIVOT operator TURNS the values of a specified column into column NAMES, effectively rotating a table.
UNPIVOT table is reverse of PIVOT Table.

A Pivot Table can automatically sort, count, and total the data stored in one table or spreadsheet and create a second table displaying the summarized data. The PIVOT operator turns the values of a specified column into column names, effectively rotating a table.
UNPIVOT table is reverse of PIVOT Table.

Catalog views return information that is used by the SQL Server Database ENGINE. Catalog Views are the most GENERAL interface to the catalog metadata and PROVIDE the most efficient way to OBTAIN, TRANSFORM, and present customized forms of this information. All user-available catalog metadata is exposed through catalog views.

Catalog views return information that is used by the SQL Server Database Engine. Catalog Views are the most general interface to the catalog metadata and provide the most efficient way to obtain, transform, and present customized forms of this information. All user-available catalog metadata is exposed through catalog views.

There are MULTIPLE ways to do this.
1) INSERT INTO SELECT
This method is used when table is already created in the database earlier and data is to be inserted into this table from ANOTHER table. If columns listed in insert clause and select clause are same, they are not required to list them.
2) SELECT INTO
This method is used when table is not created earlier and NEEDS to be created when data from one table is to be inserted into newly created table from another table. New table is created with same data types as SELECTED columns.

There are multiple ways to do this.
1) INSERT INTO SELECT
This method is used when table is already created in the database earlier and data is to be inserted into this table from another table. If columns listed in insert clause and select clause are same, they are not required to list them.
2) SELECT INTO
This method is used when table is not created earlier and needs to be created when data from one table is to be inserted into newly created table from another table. New table is created with same data types as selected columns.

There are multiple ways to do this.
1. “Detach DATABASE” from one server and “Attach Database” to another server.
2. Manually script all the objects using SSMS and run the script on NEW server.
3. Use WIZARD of SSMS.

There are multiple ways to do this.
1. “Detach Database” from one server and “Attach Database” to another server.
2. Manually script all the objects using SSMS and run the script on new server.
3. Use Wizard of SSMS.

ANSWER : Run following query in Query Editor.
USE <database_name>;
GO
SELECT SCHEMA_NAME(schema_id) AS schema_name
,NAME AS table_name
FROM sys.tables
WHERE OBJECTPROPERTY(OBJECT_ID,'IsIndexed') = 0
ORDER BY schema_name, table_name;
GO

The Transact-SQL programming language provides DBCC statements that ACT as Database Console COMMANDS for SQL SERVER. DBCC commands are used to perform following tasks.

• Maintenance tasks on database, INDEX, or filegroup.
• Tasks that gather and display various types of information.
• Validation operations on a database, table, index, catalog, filegroup, or allocation of database pages.
• Miscellaneous tasks such as enabling trace flags or removing a DLL from memory.

The Transact-SQL programming language provides DBCC statements that act as Database Console Commands for SQL Server. DBCC commands are used to perform following tasks.

• Maintenance tasks on database, index, or filegroup.
• Tasks that gather and display various types of information.
• Validation operations on a database, table, index, catalog, filegroup, or allocation of database pages.
• Miscellaneous tasks such as enabling trace flags or removing a DLL from memory.

The xml data type LETS you store XML documents and fragments in a SQL Server database. An XML fragment is an XML instance that is missing a single top-level ELEMENT. You can create columns and VARIABLES of the xml type and store XML instances in them. The xml data type and associated methods help integrate XML into the relational FRAMEWORK of SQL Server.

The xml data type lets you store XML documents and fragments in a SQL Server database. An XML fragment is an XML instance that is missing a single top-level element. You can create columns and variables of the xml type and store XML instances in them. The xml data type and associated methods help integrate XML into the relational framework of SQL Server.

Master database is system database and it contains INFORMATION about RUNNING server’s configuration. When SQL Server 2005 is installed it usually creates master, model, msdb, TEMPDB RESOURCE and distribution system database by default. Only Master database is the one which is ABSOLUTELY must have database. Without Master database SQL Server cannot be started. This is the reason it is extremely important to backup Master database.

To rebuild the Master database, Run Setup.exe, verify, and repair a SQL Server instance, and rebuild the system databases. This procedure is most often used to rebuild the master database for a corrupted installation of SQL Server.

Master database is system database and it contains information about running server’s configuration. When SQL Server 2005 is installed it usually creates master, model, msdb, tempdb resource and distribution system database by default. Only Master database is the one which is absolutely must have database. Without Master database SQL Server cannot be started. This is the reason it is extremely important to backup Master database.

To rebuild the Master database, Run Setup.exe, verify, and repair a SQL Server instance, and rebuild the system databases. This procedure is most often used to rebuild the master database for a corrupted installation of SQL Server.

RaiseError generates an error MESSAGE and initiates error processing for the session. RAISERROR can either reference a user-defined message stored in thesys.messages catalog VIEW or BUILD a message dynamically. The message is returned as a server error message to the CALLING APPLICATION or to an associated CATCH block of a TRY…CATCH construct.

RaiseError generates an error message and initiates error processing for the session. RAISERROR can either reference a user-defined message stored in thesys.messages catalog view or build a message dynamically. The message is returned as a server error message to the calling application or to an associated CATCH block of a TRY…CATCH construct.

SQL Server now supports the use of TRY…CATCH constructs for PROVIDING rich error handling. TRY…CATCH lets us build error handling at the level we need, in the way we need to, by setting a region where if any error OCCURS, it will break out of the region and head to an error handler. The basic structure is as FOLLOWS:

So if any error occurs in the TRY block, execution is DIVERTED to the CATCH block, and the error can be dealt.

SQL Server now supports the use of TRY…CATCH constructs for providing rich error handling. TRY…CATCH lets us build error handling at the level we need, in the way we need to, by setting a region where if any error occurs, it will break out of the region and head to an error handler. The basic structure is as follows:

So if any error occurs in the TRY block, execution is diverted to the CATCH block, and the error can be dealt.

Using the NOLOCK QUERY optimizer hint is generally considered good practice in order to improve concurrency on a busy system. When the NOLOCK hint is included in a SELECT statement, no locks are taken when data is read. The result is a Dirty Read, which means that ANOTHER process could be updating the data at the EXACT time you are reading it. There are no guarantees that your query will retrieve the most recent data. The ADVANTAGE to performance is that your reading of data will not block updates from taking place, and updates will not block your reading of data. SELECT statements take Shared (Read) locks. This means that MULTIPLE SELECT statements are allowed simultaneous access, but other processes are blocked from modifying the data. The updates will queue until all the reads have completed, and reads requested after the update will wait for the updates to complete. The result to your system is delay (blocking).

Using the NOLOCK query optimizer hint is generally considered good practice in order to improve concurrency on a busy system. When the NOLOCK hint is included in a SELECT statement, no locks are taken when data is read. The result is a Dirty Read, which means that another process could be updating the data at the exact time you are reading it. There are no guarantees that your query will retrieve the most recent data. The advantage to performance is that your reading of data will not block updates from taking place, and updates will not block your reading of data. SELECT statements take Shared (Read) locks. This means that multiple SELECT statements are allowed simultaneous access, but other processes are blocked from modifying the data. The updates will queue until all the reads have completed, and reads requested after the update will wait for the updates to complete. The result to your system is delay (blocking).

EXCEPT clause is similar to MINUS operation in ORACLE. The EXCEPT query and MINUS query RETURNS all rows in the first query that are not returned in the second query. Each SQL statement within the EXCEPT query and MINUS query must have the same NUMBER of FIELDS in the result sets with similar data types.

EXCEPT clause is similar to MINUS operation in Oracle. The EXCEPT query and MINUS query returns all rows in the first query that are not returned in the second query. Each SQL statement within the EXCEPT query and MINUS query must have the same number of fields in the result sets with similar data types.

SYNONYMS give you the ability to provide alternate names for database objects. You can alias object names; for example, using the EMPLOYEE table as Emp. You can also shorten names. This is especially useful when DEALING with three and FOUR PART names; for example, shortening server.database.owner.object to object.

Synonyms give you the ability to provide alternate names for database objects. You can alias object names; for example, using the Employee table as Emp. You can also shorten names. This is especially useful when dealing with three and four part names; for example, shortening server.database.owner.object to object.

YES we can write using COMMON Table Expression (CTE). A Common Table Expression (CTE) is an expression that can be thought of as a temporary result set which is defined within the EXECUTION of a single SQL statement. A CTE is similar to a derived table in that it is not stored as an OBJECT and lasts only for the duration of the query.

E.g.

Yes we can write using Common Table Expression (CTE). A Common Table Expression (CTE) is an expression that can be thought of as a temporary result set which is defined within the execution of a single SQL statement. A CTE is similar to a derived table in that it is not stored as an object and lasts only for the duration of the query.

E.g.

• Using CTE improves the readability and makes maintenance of COMPLEX queries EASY.
• The query can be divided into separate, simple, logical building blocks which can be then USED to build more complex CTEs until final result set is generated.
• CTE can be defined in functions, stored PROCEDURES, triggers or even views.
• After a CTE is defined, it can be used as a Table or a View and can SELECT, INSERT, UPDATE or DELETE Data.

• Using CTE improves the readability and makes maintenance of complex queries easy.
• The query can be divided into separate, simple, logical building blocks which can be then used to build more complex CTEs until final result set is generated.
• CTE can be defined in functions, stored procedures, triggers or even views.
• After a CTE is defined, it can be used as a Table or a View and can SELECT, INSERT, UPDATE or DELETE Data.

The GEOMETRY Type: The GEOMETRY data type is a system .NET common language runtime (CLR) data type in SQL SERVER. This type represents data in a two-dimensional Euclidean coordinate system.
The GEOGRAPHY Type: The GEOGRAPHY datatype’s functions are the same as with GEOMETRY. The difference between the two is that when you specify GEOGRAPHY, you are usually specifying points in terms of latitude and longitude.
New Date and Time Datatypes: SQL Server 2008 introduces four new datatypes related to date and time: DATE, TIME, DATETIMEOFFSET, and DATETIME2.

• DATE: The new DATE type just stores the date itself. It is based on the GREGORIAN calendar and handles YEARS from 1 to 9999.
• TIME: The new TIME (n) type stores time with a range of 00:00:00.0000000 through 23:59:59.9999999. The precision is allowed with this type. TIME supports seconds down to 100 nanoseconds. The nin TIME (n) defines this level of fractional second precision, from 0 to 7 digits of precision.
• The DATETIMEOFFSET Type: DATETIMEOFFSET (n) is the time-zone-aware version of a datetime datatype. The name will appear less odd when you consider what it really is: a date + a time + a time-zone offset. The offset is based on how far behind or ahead you are from Coordinated Universal Time (UTC) time.
• The DATETIME2 Type: It is an extension of the datetime type in earlier versions of SQL Server. This new datatype has a date range covering dates from January 1 of year 1 through December 31 of year 9999. This is a definite improvement over the 1753 LOWER boundary of the datetime datatype. DATETIME2 not only includes the larger date range, but also has a timestamp and the same fractional precision that TIME type provides

The GEOMETRY Type: The GEOMETRY data type is a system .NET common language runtime (CLR) data type in SQL Server. This type represents data in a two-dimensional Euclidean coordinate system.
The GEOGRAPHY Type: The GEOGRAPHY datatype’s functions are the same as with GEOMETRY. The difference between the two is that when you specify GEOGRAPHY, you are usually specifying points in terms of latitude and longitude.
New Date and Time Datatypes: SQL Server 2008 introduces four new datatypes related to date and time: DATE, TIME, DATETIMEOFFSET, and DATETIME2.

FILTERED Index is used to index a portion of ROWS in a table that means it applies filter on INDEX which improves query performance, reduce index maintenance COSTS, and reduce index storage costs compared with full-table indexes. When we SEE an Index created with some where clause then that is actually a FILTERED INDEX.

Filtered Index is used to index a portion of rows in a table that means it applies filter on INDEX which improves query performance, reduce index maintenance costs, and reduce index storage costs compared with full-table indexes. When we see an Index created with some where clause then that is actually a FILTERED INDEX.

CTE is an abbreviation Common Table Expression. A Common Table Expression (CTE) is an expression that can be THOUGHT of as a temporary result set which is defined within the EXECUTION of a single SQL statement. A CTE is similar to a derived table in that it is not stored as an object and LASTS only for the duration of the query.

CTE is an abbreviation Common Table Expression. A Common Table Expression (CTE) is an expression that can be thought of as a temporary result set which is defined within the execution of a single SQL statement. A CTE is similar to a derived table in that it is not stored as an object and lasts only for the duration of the query.

The TOP OPERATOR is USED to specify the number of rows to be returned by a query. The TOP operator has NEW addition in SQL SERVER 2008 that it accepts variables as well as literal values and can be used with INSERT, UPDATE, and DELETES statements.

The TOP operator is used to specify the number of rows to be returned by a query. The TOP operator has new addition in SQL SERVER 2008 that it accepts variables as well as literal values and can be used with INSERT, UPDATE, and DELETES statements.

A SPARSE COLUMN is another tool used to REDUCE the amount of physical storage used in a database. They are the ordinary columns that have an optimized storage for NULL values. Sparse columns reduce the space requirements for null values at the cost of more overhead to retrieve nonnull values.

A sparse column is another tool used to reduce the amount of physical storage used in a database. They are the ordinary columns that have an optimized storage for null values. Sparse columns reduce the space requirements for null values at the cost of more overhead to retrieve nonnull values.

Database mirroring can be USED with replication to PROVIDE availability for the publication database. Database mirroring involves two copies of a single database that typically reside on different computers. At any given time, only one copy of the database is CURRENTLY available to clients which are known as the principal database. UPDATES made by clients to the principal database are applied on the other copy of the database, known as the mirror database. Mirroring involves applying the transaction log from every insertion, UPDATE, or deletion made on the principal database onto the mirror database.

Database mirroring can be used with replication to provide availability for the publication database. Database mirroring involves two copies of a single database that typically reside on different computers. At any given time, only one copy of the database is currently available to clients which are known as the principal database. Updates made by clients to the principal database are applied on the other copy of the database, known as the mirror database. Mirroring involves applying the transaction log from every insertion, update, or deletion made on the principal database onto the mirror database.

Policy Management in SQL SERVER 2008 allows you to define and enforce policies for CONFIGURING and managing SQL Server across the enterprise. Policy-Based Management is configured in SQL Server Management STUDIO (SSMS). Navigate to the OBJECT Explorer and expand the Management NODE and the Policy Management node; you will see the Policies, Conditions, and Facets nodes.

Policy Management in SQL SERVER 2008 allows you to define and enforce policies for configuring and managing SQL Server across the enterprise. Policy-Based Management is configured in SQL Server Management Studio (SSMS). Navigate to the Object Explorer and expand the Management node and the Policy Management node; you will see the Policies, Conditions, and Facets nodes.

The master database HOLDS information for all databases located on the SQL Server instance and is theglue that holds the engine together. Because SQL Server cannot start without a functioning masterdatabase, you must administer this database with care.
The msdb database stores information regarding database backups, SQL Agent information, DTS packages, SQL Server jobs, and some REPLICATION information such as for log shipping.
The tempdb holds temporary objects such as global and local temporary tables and stored PROCEDURES.
The model is essentially a template database used in the creation of any NEW user database created in the instance.
The resoure Database is a read-only database that contains all the system objects that are included with SQL Server. SQL Server system objects, such as SYS.objects, are physically persisted in the Resource database, but they logically appear in the sys schema of every database. The Resource database does not contain user data or user metadata.

The master database holds information for all databases located on the SQL Server instance and is theglue that holds the engine together. Because SQL Server cannot start without a functioning masterdatabase, you must administer this database with care.
The msdb database stores information regarding database backups, SQL Agent information, DTS packages, SQL Server jobs, and some replication information such as for log shipping.
The tempdb holds temporary objects such as global and local temporary tables and stored procedures.
The model is essentially a template database used in the creation of any new user database created in the instance.
The resoure Database is a read-only database that contains all the system objects that are included with SQL Server. SQL Server system objects, such as sys.objects, are physically persisted in the Resource database, but they logically appear in the sys schema of every database. The Resource database does not contain user data or user metadata.

Delete command removes the rows from a table based on the condition that we provide with a WHERE clause. Truncate will actually remove all the rows from a table and there will be no data in the table after we run the truncate command.

TRUNCATE
• TRUNCATE is FASTER and uses fewer system and transaction log resources than DELETE.
• TRUNCATE removes the data by deallocating the data pages used to store the table’s data, and only the page deallocations are recorded in the transaction log.
• TRUNCATE removes all rows from a table, but the table structure, its columns, CONSTRAINTS, indexes and so on, remains. The counter used by an identity for new rows is reset to the seed for the column.
• You cannot use TRUNCATE TABLE on a table referenced by a FOREIGN KEY constraint. Because TRUNCATE TABLE is not logged, it cannot activate a TRIGGER.
• TRUNCATE cannot be rolled back.
• TRUNCATE is DDL Command.
• TRUNCATE Resets identity of the table

DELETE
• DELETE removes rows one at a time and records an entry in the transaction log for each deleted ROW.
• If you want to retain the identity counter, use DELETE instead. If you want to remove table definition and its data, use the DROP TABLE statement.
• DELETE Can be used with or without a WHERE clause
• DELETE Activates Triggers.
• DELETE can be rolled back.
• DELETE is DML Command.
• DELETE does not reset identity of the table.

Delete command removes the rows from a table based on the condition that we provide with a WHERE clause. Truncate will actually remove all the rows from a table and there will be no data in the table after we run the truncate command.

TRUNCATE
• TRUNCATE is faster and uses fewer system and transaction log resources than DELETE.
• TRUNCATE removes the data by deallocating the data pages used to store the table’s data, and only the page deallocations are recorded in the transaction log.
• TRUNCATE removes all rows from a table, but the table structure, its columns, constraints, indexes and so on, remains. The counter used by an identity for new rows is reset to the seed for the column.
• You cannot use TRUNCATE TABLE on a table referenced by a FOREIGN KEY constraint. Because TRUNCATE TABLE is not logged, it cannot activate a trigger.
• TRUNCATE cannot be rolled back.
• TRUNCATE is DDL Command.
• TRUNCATE Resets identity of the table

DELETE
• DELETE removes rows one at a time and records an entry in the transaction log for each deleted row.
• If you want to retain the identity counter, use DELETE instead. If you want to remove table definition and its data, use the DROP TABLE statement.
• DELETE Can be used with or without a WHERE clause
• DELETE Activates Triggers.
• DELETE can be rolled back.
• DELETE is DML Command.
• DELETE does not reset identity of the table.

Relational TABLES have six properties:
• Values are atomic.
• Column values are of the same KIND.
• Each ROW is UNIQUE.
• The SEQUENCE of columns is insignificant.
• The sequence of rows is insignificant.
• Each column must have a unique name.

Relational tables have six properties:
• Values are atomic.
• Column values are of the same kind.
• Each row is unique.
• The sequence of columns is insignificant.
• The sequence of rows is insignificant.
• Each column must have a unique name.

• Subject-oriented, MEANING that the data in the database is organized so that all the data elements relating to the same real-world event or object are linked together;
• TIME-variant, meaning that the changes to the data in the database are tracked and recorded so that reports can be produced showing changes over time;
• Non-volatile, meaning that data in the database is never over-written or deleted, once committed, the data is static, read-only, but retained for future reporting.
• Integrated, meaning that the database contains data from most or all of an organization’s operational applications, and that this data is MADE CONSISTENT.

• Subject-oriented, meaning that the data in the database is organized so that all the data elements relating to the same real-world event or object are linked together;
• Time-variant, meaning that the changes to the data in the database are tracked and recorded so that reports can be produced showing changes over time;
• Non-volatile, meaning that data in the database is never over-written or deleted, once committed, the data is static, read-only, but retained for future reporting.
• Integrated, meaning that the database contains data from most or all of an organization’s operational applications, and that this data is made consistent.

Identity (or AutoNumber) is a COLUMN that automatically generates numeric values. A start and increment VALUE can be set, but most DBA LEAVE these at 1. A GUID column also generates numbers; the value of this cannot be CONTROLLED. Identity/GUID columns do not need to be indexed.

Identity (or AutoNumber) is a column that automatically generates numeric values. A start and increment value can be set, but most DBA leave these at 1. A GUID column also generates numbers; the value of this cannot be controlled. Identity/GUID columns do not need to be indexed.

User-Defined FUNCTIONS allow defining its own T-SQL functions that can accept 0 or more parameters and return a single scalar data value or a table data TYPE.

Different Kinds of User-Defined Functions created are:

Scalar User-Defined Function
A Scalar user-defined function returns ONE of the scalar data types. Text, ntext, image and timestamp data types are not supported. These are the type of user-defined functions that most developers are used to in other programming languages. You pass in 0 to many parameters and you get a return value.

Inline Table-Value User-Defined Function
An Inline Table-Value user-defined function returns a table data type and is an exceptional ALTERNATIVE to a view as the user-defined function can pass parameters into a T-SQL select command and in essence provide us with a parameterized, non-updateable view of the underlying tables.

Multi-statement Table-Value User-Defined Function
A Multi-Statement Table-Value user-defined function returns a table and is also an exceptional alternative to a view as the function can support multiple T-SQL statements to build the final result where the view is limited to a single SELECT statement. Also, the ability to pass parameters into a TSQL select command or a group of them gives us the capability to in essence create a parameterized, non-updateable view of the data in the underlying tables. Within the create function command you must define the table STRUCTURE that is being returned. After creating this type of user-defined function, It can be used in the FROM clause of a T-SQL command unlike the behavior found when using a stored procedure which can also return record sets.

User-Defined Functions allow defining its own T-SQL functions that can accept 0 or more parameters and return a single scalar data value or a table data type.

Different Kinds of User-Defined Functions created are:

Scalar User-Defined Function
A Scalar user-defined function returns one of the scalar data types. Text, ntext, image and timestamp data types are not supported. These are the type of user-defined functions that most developers are used to in other programming languages. You pass in 0 to many parameters and you get a return value.

Inline Table-Value User-Defined Function
An Inline Table-Value user-defined function returns a table data type and is an exceptional alternative to a view as the user-defined function can pass parameters into a T-SQL select command and in essence provide us with a parameterized, non-updateable view of the underlying tables.

Multi-statement Table-Value User-Defined Function
A Multi-Statement Table-Value user-defined function returns a table and is also an exceptional alternative to a view as the function can support multiple T-SQL statements to build the final result where the view is limited to a single SELECT statement. Also, the ability to pass parameters into a TSQL select command or a group of them gives us the capability to in essence create a parameterized, non-updateable view of the data in the underlying tables. Within the create function command you must define the table structure that is being returned. After creating this type of user-defined function, It can be used in the FROM clause of a T-SQL command unlike the behavior found when using a stored procedure which can also return record sets.

Cross Join
A cross join that does not have a WHERE CLAUSE produces the Cartesian product of the TABLES involved in the join. The size of a Cartesian product result set is the number of rows in the first table multiplied by the number of rows in the second table. The common example is when company wants to combine each product with a pricing table to analyze each product at each price.

INNER Join
A join that displays only the rows that have a match in both joined tables is known as inner Join. This is the default type of join in the Query and View Designer.

Outer Join
A join that includes rows EVEN if they do not have related rows in the joined table is an Outer Join. You can create three different outer join to specify the unmatched rows to be included:
• Left Outer Join: In Left Outer Join all rows in the first-named table i.e. “left” table, which appears leftmost in the JOIN clause are included. Unmatched rows in the right table do not appear.
• Right Outer Join: In Right Outer Join all rows in the second-named table i.e. “right” table, which appears rightmost in the JOIN clause are included. Unmatched rows in the left table are not included.
• Full Outer Join: In Full Outer Join all rows in all joined tables are included, whether they are matched or not.

Self Join
This is a particular case when one table joins to itself, with one or two aliases to avoid confusion. A self join can be of any type, as long as the joined tables are the same. A self join is rather unique in that it involves a relationship with only one table. The common example is when company has a hierarchal reporting structure whereby one MEMBER of staff reports to another. Self Join can be Outer Join or Inner Join.

Cross Join
A cross join that does not have a WHERE clause produces the Cartesian product of the tables involved in the join. The size of a Cartesian product result set is the number of rows in the first table multiplied by the number of rows in the second table. The common example is when company wants to combine each product with a pricing table to analyze each product at each price.

Inner Join
A join that displays only the rows that have a match in both joined tables is known as inner Join. This is the default type of join in the Query and View Designer.

Outer Join
A join that includes rows even if they do not have related rows in the joined table is an Outer Join. You can create three different outer join to specify the unmatched rows to be included:
• Left Outer Join: In Left Outer Join all rows in the first-named table i.e. “left” table, which appears leftmost in the JOIN clause are included. Unmatched rows in the right table do not appear.
• Right Outer Join: In Right Outer Join all rows in the second-named table i.e. “right” table, which appears rightmost in the JOIN clause are included. Unmatched rows in the left table are not included.
• Full Outer Join: In Full Outer Join all rows in all joined tables are included, whether they are matched or not.

Self Join
This is a particular case when one table joins to itself, with one or two aliases to avoid confusion. A self join can be of any type, as long as the joined tables are the same. A self join is rather unique in that it involves a relationship with only one table. The common example is when company has a hierarchal reporting structure whereby one member of staff reports to another. Self Join can be Outer Join or Inner Join.

Sub-queries are OFTEN referred to as sub-selects, as they allow a SELECT statement to be executed arbitrarily within the BODY of another SQL statement. A sub-query is executed by enclosing it in a set of parentheses. Sub-queries are generally used to return a single row as an atomic value, THOUGH they may be used to compare values against MULTIPLE rows with the IN keyword.

A subquery is a SELECT statement that is nested within another T-SQL statement. A subquery SELECT statement if executed independently of the T-SQL statement, in which it is nested, will return a resultset. Meaning a subquery SELECT statement can standalone and is not depended on the statement in which it is nested. A subquery SELECT statement can return any number of values, and can be found in, the column list of a SELECT statement, FROM, GROUP BY, HAVING, and/or ORDER BY clauses of a T-SQL statement. A Subquery can also be used as a parameter to a function call. Basically a subquery can be used anywhere an EXPRESSION can be used.

Sub-queries are often referred to as sub-selects, as they allow a SELECT statement to be executed arbitrarily within the body of another SQL statement. A sub-query is executed by enclosing it in a set of parentheses. Sub-queries are generally used to return a single row as an atomic value, though they may be used to compare values against multiple rows with the IN keyword.

A subquery is a SELECT statement that is nested within another T-SQL statement. A subquery SELECT statement if executed independently of the T-SQL statement, in which it is nested, will return a resultset. Meaning a subquery SELECT statement can standalone and is not depended on the statement in which it is nested. A subquery SELECT statement can return any number of values, and can be found in, the column list of a SELECT statement, FROM, GROUP BY, HAVING, and/or ORDER BY clauses of a T-SQL statement. A Subquery can also be used as a parameter to a function call. Basically a subquery can be used anywhere an expression can be used.

UDF can be used in the SQL statements anywhere in the WHERE/HAVING/SELECT section where as STORED procedures cannot be. UDFs that return tables can be treated as another rowset. This can be used in JOINs with other tables. Inline UDF’s can be THOUGHT of as VIEWS that TAKE parameters and can be used in JOINs and other Rowset operations.

UDF can be used in the SQL statements anywhere in the WHERE/HAVING/SELECT section where as Stored procedures cannot be. UDFs that return tables can be treated as another rowset. This can be used in JOINs with other tables. Inline UDF’s can be thought of as views that take parameters and can be used in JOINs and other Rowset operations.