GATE CS File Organization and Indexing (B and B+ Trees) questions

An index in a DBMS is said to be dense if an index entry appears for every search-key value in the indexed file. Otherwise it is called a sparse index. Consider the following two statements. $\text{S1}$: A hash index must be a dense index $\text{S1}$: A $B^{+}$ tree index can be a sparse index Which one of the following options is correct?

Consider the following $B^{+}$tree with $5$ nodes, in which a node can store at most $3$ key values The value $23$ is now inserted in the $B^{+}$tree. Which of the following options(s) is/are CORRECT?

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: $$\mathrm{A}=(49,77,83,-), \mathrm{B}=(7,19,33,44), \mathrm{C}=\left(20^{*}, 22^{*}, 25^{*}, 26^{*}\right)$$ The $*$-marked keys signify that these are data entries in a leaf. Assume that a pointer between keys $k_{1}$ and …

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

​​​​​Which of the following file organizations is/are $\text{I/O}$ efficient for the scan operation in $\text{DBMS}$?

Consider a database of fixed-length records, stored as an ordered file. The database has $25,000$ records, with each record being $100$ bytes, of which the primary key occupies $15$ bytes. The data file is block-aligned in that each data record is fully contained within a block. The database is indexed by a primary index file, which is also stored as a …

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 $\textrm{RollNo}$. The size of a record pointer for this disk is $7$ bytes. Each student-record has a candidate key attribute called $\textrm{ANum}$ of size $12$ bytes. Suppose an index file …

Consider a database implemented using $B^+$ tree for file indexing and installed on a disk drive with block size of $\text{4 KB}$. The size of search key is $\text{12 bytes}$ and the size of tree/disk pointer is $\text{8 bytes}$. Assume that the database has one million records. Also assume that no node of the $B^+$ tree and no records are present …

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?

In a $B^+$ Tree , if the search-key value is $8$ bytes long , the block size is $512$ bytes and the pointer size is $2\;\text{B}$ , then the maximum order of the $B^+$ Tree is ____

B+ Trees are considered BALANCED because.

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

With reference to the $B^+$ tree index of order $1$ shown below, the minimum number of nodes (including the Root node) that must be fetched in order to satisfy the following query. "Get all records with a search key greater than or equal to $7$ and less than $15$ " is ______.

Consider a $B^+$ tree in which the search key is $12$ $\text{bytes}$ long, block size is $1024$ $\text{bytes}$, record pointer is $10$ $\text{bytes}$ long and the block pointer is $8$ $\text{bytes}$ long. The maximum number of keys that can be accommodated in each non-leaf node of the tree is ______.

An index is clustered, if

Consider a relational table $r$ with sufficient number of records, having attributes $A_1, A_2, \dots ,A_n$ and let $1 \leq p \leq n$. Two queries $Q1$ and $Q2$ are given below. $Q1: \pi_{A_1, \dots ,A_p} \left(\sigma_{A_p=c}\left(r\right)\right)$ where $c$ is a constant …

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?

The following key values are inserted into a $B^+$ - tree in which order of the internal nodes is $3$, and that of the leaf nodes is $2$, in the sequence given below. The order of internal nodes is the maximum number of tree pointers in each node, and the order of leaf nodes is the maximum number of data items that can be stored in it. The $B^+$ - …

A B-tree of order $4$ is built from scratch by $10$ successive insertions. What is the maximum number of node splitting operations that may take place?

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