SQL Notes

Operators are the special keywords or special characters reserved for performing particular operations and are used in the SQL queries. There is three type of operators used in SQL: Arithmetic operators: addition (+), subtraction (-), multiplication (*), division (/), etc. Logical operators: ALL, AND, ANY, ISNULL, EXISTS, BETWEEN, IN, LIKE, NOT, OR, UNIQUE. Comparison operator: … Read more

Denormalization is used to access the data from higher or lower normal form of database. It also processes redundancy into a table by incorporating data from the related tables. Denormalization adds required redundant term into the tables so that we can avoid using complex joins and many other complex operations. Denormalization doesn?t mean that normalization … Read more

Inconsistent dependency refers to the difficulty of accessing particular data as the path to reach the data may be missing or broken. Inconsistent dependency will leads users to search the data in the wrong table which will afterward give the error as an output. In the context of databases and SQL, the term “inconsistent dependency” … Read more

The major disadvantages are: The occurrence of redundant terms in the database which causes the waste of the space in the disk. Due to redundant terms inconsistency may also occur id any change will be made in the data of one table but not made in the same data of another table then inconsistency will … Read more

Normalization is mainly used to add, delete or modify a field that can be made in a single table. The primary use of Normalization is to remove redundancy and to remove the insert, delete and update distractions. Normalization breaks the table into small partitions and then link them using different relationships so that it will … Read more