Database query optimization in No-Code - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is database query optimization?

Database query optimization is the process of making database queries run faster and use fewer resources by improving how the database retrieves data.

beginner

Why is query optimization important?

It helps reduce waiting time for results, saves computer resources, and improves the overall performance of applications that use databases.

beginner

What is an index in a database?

An index is like a shortcut or a table of contents that helps the database find data quickly without scanning every row.

intermediate

How can rewriting a query improve performance?

Changing the way a query is written can help the database understand it better and use faster methods to get the data.

intermediate

What role does the database's query planner play?

The query planner decides the best way to execute a query by considering different methods and choosing the fastest one.

What does a database index do?

A Encrypts the database

B Deletes unnecessary data

C Speeds up data retrieval

D Creates backups automatically

An index helps the database find data faster, improving query speed.

Which of these can improve query performance?

A Using indexes on searched columns

B Adding more columns to the query

C Running the query multiple times

D Increasing the database size

Indexes on columns used in searches help the database find data faster.

What is the main goal of query optimization?

A Delete old data

B Use more storage space

C Make queries run slower

D Make queries run faster and use fewer resources

Query optimization aims to speed up queries and reduce resource use.

What does the query planner do?

A Deletes unused tables

B Chooses the best way to run a query

C Creates new indexes automatically

D Backs up the database

The query planner decides the fastest method to execute a query.

Which action can slow down a query?

A Scanning every row without indexes

B Filtering data early

C Using indexes

D Limiting the number of results

Scanning every row without indexes makes queries slower.

Explain in your own words why database query optimization matters in everyday applications.

Think about how slow apps feel when data takes too long to load.

Describe how using an index can change the way a database finds information.

Imagine looking up a word in a dictionary using the index.