What is Log Shipping?

Correct Answer: SQL Server can be linked to any server provided it has OLE-DB provider from Microsoft to allow a link Eg Oracle has an OLE-DB provider for oracle that Microsoft provides to add it as linked server to SQL Server group

Correct Answer: 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 Note: DELETE and TRUNCATE both can be rolled back when surrounded by TRANSACTION if the current session is not closed If TRUNCATE is written in Query Editor surrounded by TRANSACTION and if session is closed, it can not be rolled back but DELETE can be rolled back

Correct Answer: - A clustered index is a special type of index that reorders the way records in the table are physically stored Therefore table can have only one clustered index The leaf nodes of a clustered index contain the data pages - A non clustered index is a special type of index in which the logical order of the index does not match the physical stored order of the rows on disk The leaf node of a non clustered index does not consist of the data pages Instead, the leaf nodes contain index rows

Correct Answer: By default, primary key creates a clustered index on the column, whereas a unique key creates a non clustered index by default

Correct Answer: Constraints enable the RDBMS to enforce the integrity of the database automatically, without the need to create triggers, rule or defaults Types of Constraints: NOT NULL, CHEQUE, UNIQUE, PRIMARY KEY, FOREIGN KEY

Correct Answer: They get stored in System Catalog Views sysserver_principals and syssql_logins

Correct Answer: Language Integrated Query (LINQ) adds the ability to query objects using NET languages The LINQ to SQL object/relational mapping (O/RM) framework provides the following basic features: - Tools to create classes (usually called entities) mapped to database tables - Compatibility with LINQ's standard query operations - The DataContext class, with features such as entity record monitoring, automatic SQL statement generation, record concurrency detection, and much more

Correct Answer: 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

Correct Answer: 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 th 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 Setupexe, 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

Correct Answer: In SQL, UNION merges the contents of two structurally-compatible tables into a single combined table