_____ is a utility to capture a continuous record of server activity and provide auditing capability.
Answer: C
Correct answer: SQL Server Profiler
SQL Server Profiler traces events as they occur on the server - statements executed, logins, errors - and can record them for auditing or performance analysis. The Service Manager only starts and stops services.
Please log in or register to report this question.
A transaction is in the ______ state after its final statement has been executed and its changes have been written to the database.
Answer: C
Correct answer: committed
A transaction becomes partially committed when its last statement has executed but its changes are not yet certain to survive; it becomes committed once they have been written durably. The distinction is what makes recovery possible.
Please log in or register to report this question.
Which is the best file organization when data is frequently added or deleted from a file?
Answer: B
Correct answer: Direct
With direct, or hashed, organisation a record's position is computed from its key, so an insertion or deletion touches only that position. A sequential file must be rewritten to keep its order, and an index-sequential file must maintain its index as well.
Please log in or register to report this question.
______is a special type of integrity constraint that relates two relations & maintains consistency across the relations.
Answer: B
Correct answer: Referential Integrity Constraints
A referential integrity constraint links two relations: every value of the foreign key in one must exist as a primary key value in the other. That is what keeps the two tables consistent with each other; domain and entity constraints apply within a single relation.
Please log in or register to report this question.
Relational Algebra does not have
Answer: C
Correct answer: Aggregation operators.
Pure relational algebra has selection, projection, union, difference, product, join and division, but no way to compute a sum or an average - aggregation is an extension added for practical query languages. This is why SQL is more than a direct implementation of the algebra.
Please log in or register to report this question.
A table can have only one
Answer: D
Correct answer: Primary key
A table may have several candidate keys and several unique constraints, but exactly one of them is designated the primary key. The others are then alternate keys.
Please log in or register to report this question.
A DBMS is a ____ user if at most one user can use the system and is mostly restricted to personal computer systems.
Answer: C
Correct answer: Single
A single-user system allows at most one user at a time, which is why concurrency control is unnecessary in it. Multi-user systems must handle simultaneous access, which is where locking and transactions become essential.
Please log in or register to report this question.
The language that requires a user to specify the data to be retrieved without specifying exactly how to get it is
Answer: B
Correct answer: Non-Procedural DML.
A non-procedural, or declarative, language states what is wanted and leaves the system to work out how to obtain it - SQL is the example. A procedural DML would require the program to navigate to the records itself.
Please log in or register to report this question.
Which of the following is not a property of transactions?
Answer: B
Correct answer: Concurrency
The properties of a transaction are the ACID four: Atomicity, Consistency, Isolation and Durability. Concurrency is something the DBMS manages between transactions, not a property of one.
Please log in or register to report this question.
The keyword to eliminate duplicate rows from the query result in SQL is
Answer: C
Correct answer: DISTINCT
SELECT DISTINCT removes duplicate rows from the result. UNIQUE is a constraint declared on a column when the table is defined; it prevents duplicates being stored rather than filtering them out of a query.
Please log in or register to report this question.
