Databases · Junior · Question 44 of 75

Why not add an index on every column?

1PostgreSQL allows only one index per table
2Indexes make SELECT queries slower
✓Correct answer: Each index slows down inserts and updates and takes disk space and memory

Explanation

Add indexes for real query patterns and remove unused ones. PostgreSQL's statistics views show how often each index is used.

Further reading

PostgreSQL: Indexes ↗

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