What is the job of the information stored in data-dictionary?
The information in the data dictionary validates the existence of the objects, provides access to them, and maps the actual physical storage location. Read more »
‘Database Interview Questions’ - KyaPoocha.com
Are the resulting relations of PRODUCT and JOIN operation the same?
PRODUCT: Concatenation of every row in one relation with every row in another. JOIN: Concatenation of rows from one relation and related rows from another. Read more »
What are the unary operations in Relational Algebra?
PROJECTION and SELECTION. Read more »
What do you mean by flat file database?
It is a database in which there are no programs or user access languages. It has no cross-file capabilities but is user-friendly and provides user-interface management. Read more »
What is “transparent DBMS”?
It is one, which keeps its Physical Structure hidden from user. Read more »
What is a Phantom Deadlock?
In distributed deadlock detection, the delay in propagating local information might cause the deadlock detection algorithms to identify deadlocks that do not really... Read more »
What is durability in DBMS?
Once the DBMS informs the user that a transaction has successfully completed, its effects should persist even if the system crashes before all its changes are reflected... Read more »
What is Lossless join property?
It guarantees that the spurious tuple generation does not occur with respect to relation schemas after decomposition. Read more »
What is 1 NF (Normal Form)?
The domain of attribute must include only atomic (simple, indivisible) values. Read more »
What is Fully Functional dependency?
It is based on concept of full functional dependency. A functional dependency X Y is full functional dependency if removal of any attribute A from... Read more »
What is 2NF?
A relation schema R is in 2NF if it is in 1NF and every non-prime attribute A in R is fully functionally dependent on primary key. Read more »
What is 3NF?
A relation schema R is in 3NF if it is in 2NF and for every FD X A either of the following is true X is a Super-key of R. A is a prime attribute of R. In other... Read more »
What is BCNF (Boyce-Codd Normal Form)?
A relation schema R is in BCNF if it is in 3NF and satisfies an additional constraint that for every FD X A, X must be a candidate key. Read more »
What is 4NF?
A relation schema R is said to be in 4NF if for every Multivalued dependency X Y that holds over R, one of following is trueX is subset or equal to (or)... Read more »
What is 5NF?
A Relation schema R is said to be 5NF if for every join dependency {R1, R2, …, Rn} that holds R, one the following is true Ri = R for some i.The join dependency... Read more »
What is Relational Algebra?
It is procedural query language. It consists of a set of operations that take one or two relations as input and produce a new relation. Read more »
What is Relational Calculus?
It is an applied predicate calculus specifically tailored for relational databases proposed by E.F. Codd. E.g. of languages based on it are DSL ALPHA, QUEL. Read more »
What is DDL Interpreter?
It interprets DDL statements and record them in tables containing metadata. Read more »
What is Query evaluation engine?
It executes low-level instruction generated by compiler. Read more »
What is DML Compiler?
It translates DML statements in a query language into low-level instruction that the query evaluation engine can understand. Read more »