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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Q. If needed to split a node or coalesce it with its siblings, or redistribute key values between siblings, the crabbing protocol locks the parent of the node in ____________ mode.

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Q. In crabbing protocol to inset or delete a key value the leaf node has to be locked in ___________ mode.

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Q. B-link tree requires a pointer to its __________ sibling.

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Q. Instead of locking index leaf nodes in a two-phase manner, some index concurrency-control schemes use ___________ on individual key values, allowing other key values to be inserted or deleted from the same leaf.

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Q. The recovery scheme must also provide

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Q. Which one of the following is a failure to system

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