The organization, storage, querying, and management of data. General program algorithms remain in Coding.
Test your knowledge with these top questions!
What does ORDER BY do to SQL query results?
ORDER BY sorts after the database finds matches, so filtering happens before the final order.
What is the main purpose of database replication?
Replicas can copy accidental deletions too, so extra live copies do not automatically protect against human mistakes.
In a normalized sales database, which detail belongs with an order item rather than the product?
The same product can appear in many orders with a different quantity each time, so quantity belongs with each purchase.
In a database, what is an ID created only for record identification, with no business meaning, called?
Generated customer numbers can stay fixed even when a customer's name or email address changes.
A database replica has not yet received a saved profile update. What is the delay called?
A page can show an old profile even after a successful save if the next request reads from a replica that is still catching up.
In a time-series database, which field places a temperature reading on a timeline?
Several sensors can share a timestamp, so the sensor identity helps distinguish their separate readings.
In a graph database, which relationship needs a direction to distinguish the two people's roles?
An arrow from parent to child lets a family graph tell ancestors from descendants across several generations.
In ETL for a data warehouse, which step cleans and standardizes incoming data?
Converting sales to one currency lets reports add amounts from stores in different countries.
In a graph database, which part typically represents a person, place, or product?
One person node can connect to both friends and employers, keeping that person's details in one place.
In a theater database with one ticket price, which pair identifies a seat when numbers repeat in each row?
A key that uses several columns together is called a composite key, even when no single column identifies the record.