Start Discovering Solved Questions and Your Course Assignments
TextBooks Included
Active Tutors
Asked Questions
Answered Questions
what is a database graphthe partial ordering implies that the set d may now be viewed as a directed acyclic graph known as a database
define upgrade and downgradeit gives a mechanism for conversion from shared lock to exclusive lock is called as upgradeit gives a mechanism for
define the phases of two phase locking protocolgrowing phase a transaction may get locks but not release any lockshrinking phase a transaction might
what is deadlockneither of the transaction can ever proceed with its normal implementation this situation is known as
define locklock is the most common used to execute the requirement is to permit a transaction to access a data item only if it is currently holding a
what are the two types of serializabilitythe two types of serializability isa conflict serializabilityb view
what is average response timethe average response time is that the average time for a transaction to be done after it has been
give the reasons for allowing concurrencythe reasons for allowing concurrency is if the transactions run serially a short transaction might have to
what is a shadow copy schemeit is simple but efficient scheme known as the shadow copy schemes it is based on making copies of the database called
what are the states of transactionthe states of transaction are-a activeb partially committedc failedd abortede committed f
when is a transaction rolled backany changes that the aborted transaction made to the database must be uncompleted while the changes caused by an
what is recovery management componentensuring durability is the responsibility of a software component of the base system known as the recovery
what are the properties of transactionthere are three properties of transactions -a atomicityb
what are the two statements regarding transactionthe two statements regarding transaction of the form are-a begin
what is transactioncollections of operations that form a single logical unit of work are known as
what is known as fudge factorthe number of partitions is enhanced by a small value called the fudge factor which is usually 20 percent of the number
what is called as an n-way mergethe merge operation is a generalization of the two-way merge used by the standard in-memory sort-merge algorithm it
what is called as recursive partitioningthe system repeats the splitting of the input unless each partition of the build input fits in the memory
what is called a query -execution enginethe query implementation engine takes a query evaluation plan implements that plan and returns the answers to
what is called a query evaluation plana sequence of primitive operations that can be used to assess a query is a query evaluation plan or a query
what is called an evaluation primitivea relational algebra operation annotated with instructions on how to evaluate is known as an evaluation
what is called query processingquery processing refers to the range of activities included in extracting data from a
what is a hash indexa hash index organizes the search keys with their associated pointers into a hash file
what is a b-tree indexa b-tree index takes the form of a balanced tree in which each path from the root of the root of the root of the tree to a leaf
what is b-treea b-tree eliminates the redundant storage of search-key values it permits search key values to appear only