Indexing & Storage

An index in a DBMS is said to be dense if an index entry appears for every searchkey value in the indexed file. Otherwise it is called a sparse index. Consider the following two statements. S1: A hash index must be a den...

In a $\mathrm{B}^{+}$- tree where each node can hold at most four key values, a root to leaf path consists of the following nodes: $$A=(49,77,83,-), B=(7,19,33,44), C=\left(20^*, 22^*, 25^*, 26^*\right)$$ The *-marked ke...

In a B+ tree, the requirement of at least half-full (50%) node occupancy is relaxed for which one of the following cases?

A data file consisting of 1,50,000 student-records is stored on a hard disk with block size of 4096 bytes. The data file is sorted on the primary key RollNo. The size of a record pointer for this disk is 7 bytes. Each st...

Consider a database implemented using B+ tree for file indexing and installed on a disk drive with block size of 4 KB. The size of search key is 12 bytes and the size of tree/disk pointer is 8 bytes. Assume that the data...

Which one of the following statements is NOT correct about the B + tree data structure used for creating an index of a relational database table?

B + Trees are considered BALANCED because

A file is organized so that the ordering of data records is the same as or close to the ordering of data entries in some index. Then that index is called

Consider a B + tree in which the search key is 12 bytes long, block size is 1024 bytes, record pointer is 10 bytes long and block pointer is 8 bytes long. The maximum number of keys that can be accommodated in each non-l...

Consider a relational table r with sufficient number of records, having attributes A 1 , A 2 ,....., A n and let 1 $$ \le $$ p $$ \le $$ n. Two queries Q1 and Q2 are given below. $$Q1: \pi_{A_1, \dots ,A_p} \left(\sigma_...

Consider a B + - tree in which the maximum number of keys in a node is 5. What is the minimum number of keys in any non-root node?

Consider a file of 16384 records. Each record is 32 bytes long and its key field is of size 6 bytes. The file is ordered on a non-key field, and the file organization is unspanned. The file is stored in a file system wit...

A clustering index is defined on the fields which are of type

The order of a leaf node in a B + - tree is the maximum number of (value, data record pointer) pairs it can hold. Given that the block size is 1K bytes, data record pointer is 7 bytes long, the value field is 9 bytes lon...

A B-Tree used as an index for a large database table has four levels including the root node. If a new key is inserted in this index, then the maximum number of nodes that could be newly created in the process are:

Consider a table T in a relational database with a key field K. A B-tree of order p is used as an access structure on K, where p denotes the maximum number of tree pointers in a B-tree index node. Assume that K is 10 byt...

The order of an internal node in a B + tree index is the maximum number of children it can have. Suppose that a child pointer takes 6 bytes, the search field value takes 14 bytes, and the block size is 512 bytes. What is...

A B + - tree index is to be built on the Name attribute of the relation STUDENT. Assume that all student names are of length 8 bytes, disk blocks are of size 512 bytes, and index pointers are of size 4 bytes. Given this...

B + -trees are preferred to binary trees in databases because

Which of the following is correct?

There are five records in a database. Name Age Occupation Category Rama 27 CON A Abdul 22 ENG A Jennifer 28 DOC B Maya 32 SER D Dev 24 MUS C There is an index file associated with this and it contains the values 1, 3, 2,...