Why indexing strategy matters in PostgreSQL - Quick Recap

Recall & Review

beginner

What is the main purpose of an index in a database?

An index helps the database find data faster, like a book's table of contents helps you find a chapter quickly.

intermediate

How can a bad indexing strategy affect database performance?

It can slow down data updates and use extra storage, making the database less efficient overall.

beginner

Why should you avoid indexing every column in a table?

Because each index takes space and slows down data changes, so only important columns should be indexed.

beginner

What type of queries benefit most from a well-planned index?

Queries that search or filter data using specific columns, like looking up a customer by ID or name.

beginner

How does PostgreSQL use indexes to improve query speed?

PostgreSQL uses indexes to quickly locate rows without scanning the whole table, saving time and resources.

What happens if you add too many indexes to a table?

A Data insertion and updates become slower

B Queries always run faster

C The database size decreases

D Indexes automatically remove duplicates

Too many indexes slow down data changes because each index must be updated.

Which type of query benefits most from an index?

A Deleting the entire table

B Full table scans

C Inserting new rows

D Filtering rows by a specific column value

Indexes speed up queries that filter or search by specific column values.

Why is indexing every column not recommended?

A It makes queries slower

B It uses too much disk space and slows updates

C It deletes data accidentally

D It causes syntax errors

Each index uses space and slows down data modifications.

What is a good indexing strategy?

A Index only columns used often in queries

B Index all columns regardless of use

C Never use indexes

D Index only primary keys

Indexing columns frequently used in queries improves performance without overhead.

How does PostgreSQL use an index during a query?

A To scan the entire table faster

B To backup data automatically

C To jump directly to matching rows

D To delete rows quickly

Indexes let PostgreSQL jump to matching rows without scanning all data.

Explain why having a good indexing strategy matters for database performance.

Think about how indexes help find data and what happens when there are too many.

Describe how PostgreSQL uses indexes to improve query speed.

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