File Structure
This method stores new file records at the end and requires a linear search to find a record.
Unordered file
This type of index has one entry per record in the data file and is typically used for secondary indexes.
Dense index
In this index type, all data record pointers exist only in the leaf nodes.
B+-tree
This basic operation retrieves specific rows from a table based on a condition.
SELECT
Most of modern DBMS use this type of optimizer that evaluates multiple plans and chooses the one with the lowest estimated cost.
CBO
In file storage, this term refers to the number of records that can be stored in one block.
Blocking factor
This multilevel indexing method reduces the number of block accesses by creating indexes over indexes.
Multi-level index
What happens in a B-tree when a node becomes more than half full after insertion?
Split
This method of join scans one relation entirely for each tuple of another relation.
Nested-loop join
This cost component includes disk reads and writes, and is often the most significant in query optimization.
I/O
A record that exceeds the size of a block and is split across multiple blocks is known as this.
Spanned record
What is the index blocking factor (Bfrᵢ) when the index entry size is 100 bytes and block size is 512 bytes?
5
In a B-tree of order p, how many children pointers can each node have at most?
p
This relational algebra operation is used to pick specific columns from a relation.
PROJECT
The ratio of selected records to total records in a file is called this.
Selectivity
In external hashing, this value determines the specific bucket a record is stored in.
Hash Key
What’s the maximum number of block accesses in a three-level multilevel index?
4 (3 + 1)
What structural property ensures that all leaf nodes in a B-tree or B+-tree are at the same level?
Balance
This sorting-based algorithm is often used to merge large datasets that don’t fit in memory.
Sort-merge
In cost-based optimization, this tree structure is used to execute relational algebra operations.
Query tree
This hashing method allows expansion by splitting blocks in linear order without a directory.
Linear Hashing
In multilevel indexing, this term refers to the number of index entries a single index block can hold and affects the number of index levels required.
fan-out (or index blocking factor)
Given a block size of 512 bytes, a data pointer size of 7 bytes, and search field size of 9 bytes, what is the maximum number of data entries a B+-tree leaf node can hold?
31
In query processing, this brute-force method checks every record in a file for a condition.
Linear Search
In cost-based optimization, this system catalog information includes details like the number of records, average row length, and number of blocks.
Catalog (Metadata)