Semantic query optimisation is a technique to modify one query into another query by using the _________ database constraints
Semantic query optimisation is a technique to modify one query into another query by using the _________ database constraints
_______ lookup starts with the sub-query and processes one sub-query row at one time..
_______ lookup starts with the sub-query and processes one sub-query row at one time..
Materialised (stored) evolution specifies that the result of operations can be stored as _________ relation.
Materialised (stored) evolution specifies that the result of operations can be stored as _________ relation.
______ search is faster and more efficient than the linear search has the search space is reduced to half in each comparison
______ search is faster and more efficient than the linear search has the search space is reduced to half in each comparison
A greedy strategy works in a _______ manner
A greedy strategy works in a _______ manner
if two operations produce same result they are said to be __________.
if two operations produce same result they are said to be __________.
If the query checks for equality between the key attribute and the primary index then __________search might be used
If the query checks for equality between the key attribute and the primary index then __________search might be used
_________ operation performs the task of retrieving the desired records from the database.
_________ operation performs the task of retrieving the desired records from the database.
The worst case performance comes with minimum value of dM as ____________.
The worst case performance comes with minimum value of dM as ____________.
____________ technique can be used for framing proficient algorithms for problems like view/index selection, query result caching and maintenance.
____________ technique can be used for framing proficient algorithms for problems like view/index selection, query result caching and maintenance.
The number of initial runs and the size of a run (nR) are governed by the number of ________ and available ___________.
The number of initial runs and the size of a run (nR) are governed by the number of ________ and available ___________.
_________scan retrieves all the records from the file and checks whether the attribute values qualify the criteria or not.
_________scan retrieves all the records from the file and checks whether the attribute values qualify the criteria or not.
_______ lookup firstly starts executing the outer query and when outer rows are generated then it invokes the sub-query
_______ lookup firstly starts executing the outer query and when outer rows are generated then it invokes the sub-query
For the conversion of this tree into an execution plan, which are not the requirements of the optimiser ?
For the conversion of this tree into an execution plan, which are not the requirements of the optimiser ?
If they scan entire file and then retrieve the records satisfying the user defined condition they are termed as________scans.
If they scan entire file and then retrieve the records satisfying the user defined condition they are termed as________scans.
if the search algorithm carries an index, then that search is termed as ________ scan..
if the search algorithm carries an index, then that search is termed as ________ scan..
Sortmerge strategy divides the main file into sub-files of smaller size termed as _________.
Sortmerge strategy divides the main file into sub-files of smaller size termed as _________.
If u want to retrieves the names of employees who earn more than their Supervisors then the query will be______________
If u want to retrieves the names of employees who earn more than their Supervisors then the query will be______________
_______ is defined as a set of rows which is used to encode the changes to a specific base table
_______ is defined as a set of rows which is used to encode the changes to a specific base table
__________ provides various algorithms for implementing the different types of relational operations that appear in a query execution strategy.
__________ provides various algorithms for implementing the different types of relational operations that appear in a query execution strategy.