Category Archives: DBMS

Canonical Cover

3.4

Whenever a user updates the database, the system must check whether any of the functional dependencies are getting violated in this process. If there is… Read More »

RAID

2.5

RAID, or “Redundant Arrays of Independent Disks” is a technique which makes use of a combination of multiple disks instead of using a single disk… Read More »

SQL | ALL and ANY

2

ALL & ANY are logical operators in SQL. They return boolean value as a result. ALL ALL operator is used to select all tuples of… Read More »

SQL | NULL

1.5

SQL supports a special value known as NULL which is used to represent the values of attributes that may be unknown or not apply to… Read More »

SQL | EXISTS

2.5

The EXISTS condition in SQL is used to check whether the result of a correlated nested query is empty (contains no tuples) or not. The… Read More »