Q. ANSI-standard SQL allows the use of special operators in conjunction with the WHERE clause. A special operator used to check whether an attribute value is null is

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Q. A lock that prevents the use of any tables in the database from one transaction while another transaction is being processed is called a

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Q. A condition that occurs when two transactions wait for each other to unlock data is known as a(n)

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Q. Which of the following is not true about B+ trees?

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Q. The extent of the database resource that is included with each lock is called the level of

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Q. Snapshot isolation is a particular type of ______________ scheme.

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Q. Snapshot isolation is used to give

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Q. Lost update problem is

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Q. Under first updater wins the system uses a __________ mechanism that applies only to updates.

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Q. When a transaction Ti attempts to update a data item, it requests a _________ on that data item.

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Q. Each of a pair of transactions has read data that is written by the other, but there is no data written by both transactions, is referred to as

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Q. An application developer can guard against certain snapshot anomalies by appending a ______ clause to the SQL select query.

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Q. Evaluate the CREATE TABLE statement:

CREATE TABLE products
(product_id NUMBER(6) CONSTRAINT prod_id_pk PRIMARY KEY, product_name VARCHAR2(15));

Which statement is true regarding the PROD_ID_PK constraint?

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Q. Evaluate the following CREATE SEQUENCE statement:

CREATE SEQUENCE seq1
START WITH 100
INCREMENT BY 10
MAXVALUE 200
CYCLE
NOCACHE;

The sequence SEQ1 has generated numbers up to the maximum limit of 200. You issue the following SQL statement:

SELECT seq1.nextval FROM dual;

What is displayed by the SELECT statement?

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Q. The method of access that uses key transformation is called as

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Q. Why do we need concurrency control on B+ trees ?

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Q. How many techniques are available to control concurrency on B+ trees?

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Q. In crabbing protocol locking

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Q. The deadlock can be handled by

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Q. In crabbing protocol the the lock obtained on the root node is in _________ mode.

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