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define outer joinouter join - if there are any type of values in the one table that do not have corresponding values in the other in an equi-join
explain deadlock detection and recoverydeadlock detection - a deadlock is said to take place when there is a circular chain of transaction every
explain clustering file organizationi determine if a record of file is physically ordered on a nonkey field - that does not comprise a different
what is a checkpoint list the operations to be performed by the system when a checkpoint is to be taken what does the recovery system do if there is
explain the log based recovery methodthe system log that is generally written on stable storage consists of the redundant data required to recover
discuss the difference between drop table r and delete from r drop table command deletes all the records with the table definition this command
explain the check clausethe check clause is employed to at the end of a create table statement specify table constraints this is known as table-based
discuss the count functionthe count function used returns the number of tuples or values fixed in a querythe count function comprises two types of
how nulls are treated in comparison operatoralong with comparison relational operators the null values are ignored as we cannot derive the relation
what is difference between primary index and secondary indexprimary indexa it is an ordered file whose records are of fixed length along with two
what are the disadvantages of file-processing system ans the disadvantages of file-processing systema data redundancy and inconsistency - data
explain the project-join normal forma relation r is in pjnf along with respect to a set of functional dependencies d if for all join dependencies of
explain the exec statement in sqlans exec statement has the structure exec sql ltembedded sql statementgt end-exec embeded sql statements
define cascading rollbackthe phenomenon where a single transaction failure leads to a series of transaction rollbacks is known as cascading
define the attribute inheritancethe attributes of a higher level entity set are inherited through a lower level entity set made by
define granularity hierarchy of granularity of locks amp multiple granularity locking explain the modified two phase locking along with multiple
when are two schedules said to be view equivalent ans two schedules that is denoted as s and s are said to be view equivalent if the
what are the objectives of query processing ans the objectives of query processing is to transform a query written in a high
describe the definition of a transaction in sql ans the sql transaction starts implicitly transactions are finished by either commit work that
difference between left outer join and right outer joinin left outer join tuples from the left-hand-side relation which do not match any tuple in the
explain the difference between drop and deletedelete deletes one or more than one tuples of a particular relation from the database drop is employed
what is the difference between where and having clausespredicates in the where clause applies to every tuple while the predicate in the having clause
differentiate between a subquery and a joinif we need to acquire information from one or more tables after that either subquery or join can be used
explain the structure of well formed formulae in relational calculusans a an atom is a formulab if p1 is a formula after that so are notp1 and p1c if
define cardinality and participation constraints on a relationship type completeness constraint on generalization ans