1.In a wait-for graph, an edge drawn from transaction T1 to T2 indicates that-
Select one:
a.T1 reads a data item before T2 reads the same.
b.T2 waits on T1 (for some data item to be released).
c.T2 reads a data item before T1 reads the same.
d.T1 waits on T2 (for some data item to be released).
Answer:d
2.It is possible to construct a secondary index on a unique non-ordering attribute/field of a relation.
Select one:
True
False
Answer: True
3.In a B+ tree, if the block size is 1024 Bytes, record size is 148 Bytes, key field length is 12 Bytes, Block pointer length is 6 Bytes, the max. number of keys in each internal node of the B+ tree is___.
Select one:
a.57
b.58
c.56
d.55
Answer: 56
4.A transaction can abort/fail even after its entering into partially committed state.
Select one:
True
False
Answer: True
5.Which of the following actions is idempotent?
Select one:
a.both redo and undo
b.Redo
c.Undo
d.none
Answer: b
6.Assume that we have 5246 index blocks in the third level of a multilevel Indexing structure. If the Block size is 512 Bytes and the blocking factor for Index file is 40, then we need __ number of index blocks at 4th level. Assume unspanned records organization.
Select one:
a.13
b.132
c.11
d.26
Answer: b
7.In a precedence graph schedules become nodes.
Select one:
True
False
Answer: False
8.The concept of Checkpointing in database recovery avoids ___.
Select one:
a.Unnecessary concurrency during the recovery process.
b.Unnecessary redo operations during the recovery process.
c.Early transaction failures during the recovery process.
d.Unnecessary locks during the recovery process.
Answer: b
9.We can have more than one clustering index for a give relation.
Select one:
True
False
Answer: False
10. Database Tuning is the activity that is performed after deploying the database and the related Applications.
Select one:
True
False
Answer: True
11.If the order (p) of the B+ tree is 7, then the minimum number of keys in any internal node is-
Select one:
a.3
b.6
c.2
d.4
Answer: d
12.Assume a scenario, where we use Timestamp-based concurrency control protocol. Consider that a data item X has been written by 5 transaction, as mentioned below, with corresponding timestamps, in the same order-
TS-235; TS-219; TS-240; TS-225; TS-237.
Then the Write Timestamp of the data item X is___.
Select one:
a.235
b.219
c.240
d.237
Answer: c
13. If we have two transactions T1 and T2 in a schedule S, and if T2 reads a data item A before T1 reads it, then in the corresponding precedence graph, we can introduce an edge from T2 to T1.
Select one:
True
False
Answer: False
14. A transaction enters committed state immediately after__
Select one:
a.permanently writing the log to the Disk
b.writing the updates to the log available in the buffer
c.executing the last operation
d.Anytime
Answer: a
15.A Query Graph gives/incorporates details about the order in which the operations are to be executed for a query.
Select one:
True
False
Answer: b
16.If we have 18456 data blocks and 355 Index blocks in a Primary indexing scheme, then the number of block accesses needed to retrieve a record with given key value is____.
Select one:
a.12
b.11
c.10
d.9
Answer: c
17.In a B+ tree, we can find a pointer to the record with given key value, at any level.
Select one:
True
False
Answer: False
18.The Two-phase locking protocol will always avoid/prevents deadlocks.
Select one:
True
False
Answer: False
19.In timestamp based concurrency control protocol, we can apply shared and/or exclusive locks to data items.
Select one:
True
False
Answer: False
20.In a multilevel Indexing scheme (with root), the number of block accesses required to access a record with given key value is dependent on___.
Select one:
a.Number of Index blocks in the first level
b.Number of data blocks
c.Number of index levels
d.fanout of the Index block
Answer: c
21. In shadow paging based recovery approach, modified data blocks of a file are pointed to by the shadow page-table or shadow-page directory.
Select one:
True
False
Answer: False
22.If there are 32000 records, and the record size is 120 Bytes; and the block size is 512 Bytes. And if the records are ordered based on the key attribute. Then what is worst case number of block accesses required to access a record with given key value? Hint: binary search can be applied on the key attribute value. Assume unspanned record organization. Note: there is no Indexing is done.
Select one:
a.12
b.10
c.11
d.13
Answer: d
23.An Index created on non-ordering key-field is a Dense index.
Select one:
True
False
Answer: False
24.If the block size is 1024 Bytes, and we have 32678 records in a file and each record size is 132 Bytes, then the Blocking factor for Data file is_____. (Assume unspanned records organization).
Select one:
a.10
b.7
c.32
d.8
Answer: b
25.If a schedule S2 is conflict equivalent to another schedule S1; and schedule S3 is conflict equivalent to schedule S2, it does not imply that S1 and S3 are conflict equivalent.
Select one:
True
False
Answer: False
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