De-normalization is the process of attempting to optimize the performance of a database by adding redundant data. It is sometimes necessary because current DBMS’s implement the relational model poorly. A true relational DBMS would allow for a fully normalized database at the logical level, while providing physical storage of data… Continue reading
Both primary key and unique key enforces uniqueness of the column on which they are defined. But by default primary key creates a clustered index on the column, where are unique creates a nonclustered index by default. Another major difference is that, primary key doesn’t allow NULLs, but unique key… Continue reading
To rename db sp_renamedb ‘old_database_name’ , ‘new_database_name’ If someone is using db it will not accept sp_renmaedb. In that case first bring db to single user using sp_dboptions. Use sp_renamedb to rename database. Use sp_dboptions to bring database to multi user mode. E.g. USE master; EXEC sp_dboption AdventureWorks, ‘Single User’,… Continue reading
Database normalization is a data design and organization process applied to data structures based on rules that help building relational databases. In relational database design, the process of organizing data to minimize redundancy is called normalization. Normalization usually involves dividing a database into two or more tables and defining relationships… Continue reading
An index is a physical structure containing pointers to the data. Indices are created in an existing table to locate rows more quickly and efficiently. It is possible to create an index on one or more columns of a table, and each index is given a name. The users cannot… Continue reading
A FOREIGN KEY constraint prevents any actions that would destroy links between tables with the corresponding data values. A foreign key in one table points to a primary key in another table. Foreign keys prevent actions that would leave rows with foreign key values when there are no primary keys… Continue reading
A UNIQUE KEY constraint enforces the uniqueness of the values in a set of columns, so no duplicate values are entered. The unique key constraints are used to enforce entity integrity as the primary key constraints.
A PRIMARY KEY constraint is a unique identifier for a row within a database table. Every table should have a primary key constraint to uniquely identify each row and only one primary key constraint can be created for each table. The primary key constraints are used to enforce entity integrity.
A CHECK constraint is used to limit the values that can be placed in a column. The check constraints are used to enforce domain integrity.
In SQL Management Studio all login name & password and server name are stored in a file and its name is “SqlStudio.bin” and its location is “%AppData%\Microsoft\Microsoft SQL Server\100\Tools\Shell\” OR “AppData\Roaming\Microsoft\SQL Server Management Studio\11.0\” OR any other location because location is depends on SQL Server Version. But remember its file… Continue reading