Understanding databases Flashcards
General questions to test knowledge about databases
What is a database?
A structured data storage designed to allow ease of data accessibility, manipulation, and manageability.
What describes a structured data storage designed for accessibility and manipulation?
A database.
Why do businesses prefer databases over file storage?
Because databases ensure data integrity, enable efficient querying, apply constraints, and offer security through authentication and authorization.
If you want data that is easy to access, manage, and manipulate, what should you use?
A database.
Explain in your own words why a database is better than using files for storing important business data.
Databases enforce rules, make data retrieval faster, prevent errors, and secure the data.
What is structured data?
Data that can be organized in tables, like relational databases, Excel spreadsheets, or bank transaction logs.
Give three examples of structured data.
Relational database customer records, Excel employee salary spreadsheet, Bank transaction log.
What kind of data fits well in relational databases?
Structured data with defined formats and fields.
How does structured data help with analysis?
It is easy to query, aggregate, and perform analytics using SQL.
What is unstructured data?
Data that does not fit into tables and has no fixed format.
Give three examples of unstructured data.
Social media posts, scanned contracts in PDF, MP3 audio files of customer service calls.
Why can’t unstructured data be directly queried in a relational database?
Because it lacks a predefined format that fits table structures.
How is unstructured data typically handled?
Using NoSQL databases or specialized data processing tools.
List four advantages of using a database over file storage.
Data integrity, efficient querying, constraint enforcement, and improved security.
What does the ACID principle stand for?
Atomicity, Consistency, Isolation, Durability.
What does Atomicity ensure in databases?
That transactions fully succeed or fully abort, preventing partial data updates.
What does Consistency ensure in databases?
That the data remains valid and correct before and after a transaction.
What does Isolation ensure in databases?
That transactions do not interfere with each other.
What does Durability ensure in databases?
That completed transactions are permanently saved.
What happens in a file system if there’s an error in data entry?
The system saves whatever is entered, even if it’s incorrect, because file systems lack constraints.
Why are queries more efficient than scanning files?
Queries access only the needed data directly, while file scanning requires reading the whole file.
How does a database provide better security than a file system?
Databases use authentication and authorization to control data access.
Why is it risky to store sensitive data in plain files?
Because file systems lack robust access control and integrity checks.
Name four main types of databases.
Relational databases, NoSQL databases, Graph databases, Object-oriented databases.
Which type of database is best for relationships between entities?
Relational databases.
Which database type is preferred for flexible, unstructured data?
NoSQL databases.
Which database type focuses on relationships and connections between data points?
Graph databases.
What database type stores data as objects, similar to object-oriented programming?
Object-oriented databases.
