Lesson 58/100

Tutorials PostgreSQL Tutorial

Full-Text Search — Complete Guide

Full-Text Search — Complete Guide: free step-by-step lesson with examples, common mistakes, and interview tips — part of PostgreSQL Tutorial on Toolliyo Academy.

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PostgreSQL Tutorial · Lesson 58 of 100

Full-Text Search

SQL ✓Advanced

Advanced · 2 — Production · ~10 min · PostgreSQL — JSONB & Modern Features

What is this?

Full-text search tokenizes documents into tsvector and matches tsquery — ranked by ts_rank, accelerated with GIN index on to_tsvector output.

Why should you care?

PostgresVerse blog and product description search beats ILIKE '%phone%' that cannot use indexes.

See it live — copy this example

Run in pgAdmin or psql.

ALTER TABLE products ADD COLUMN search_doc tsvector
  GENERATED ALWAYS AS (
    to_tsvector('english', coalesce(name,'') || ' ' || coalesce(description,''))
  ) STORED;

CREATE INDEX idx_products_fts ON products USING GIN (search_doc);

SELECT name, ts_rank(search_doc, query) AS rank
FROM products, plainto_tsquery('english', 'wireless keyboard') query
WHERE search_doc @@ query
ORDER BY rank DESC
LIMIT 10;

What happened?

  • Generated tsvector column combines name and description.
  • GIN index supports @@ match.
  • plainto_tsquery parses user phrase; ts_rank orders relevance.

Practice next

  1. Add description text column with sample prose.
  2. Create generated search_doc and GIN index.
  3. Search varied phrases; try typo — note no fuzzy by default.
  4. Weight fields with setweight on name vs description.
  5. Add unaccent extension for café vs cafe matching.

Remember

tsvector + tsquery + GIN is PostgreSQL FTS stack. Generated columns keep index in sync. pg_trgm adds fuzzy/substring complement.

Marketplace search box uses FTS; ranks in-stock items higher in app layer.

Outcome: Search P95 60ms vs 4s ILIKE on catalog table.

Interview prep for this lesson

Practice these questions aloud after reading—each links to a full structured answer.

Junior Detailed
Explain SQL queries in the context of PostgreSQL.
Short answer: Interviewers want a crisp definition, a practical example from your projects, and awareness of trade-offs—not textbook dumps. Explain a bit more How to structure your answer (60–90 seconds) Define SQL queri…
Mid Detailed
What are common mistakes teams make with Schema design when using PostgreSQL?
Short answer: Interviewers want a crisp definition, a practical example from your projects, and awareness of trade-offs—not textbook dumps. Explain a bit more How to structure your answer (60–90 seconds) Define Schema de…
Senior Detailed
How would you debug a production issue related to Transactions in a PostgreSQL application?
Short answer: Interviewers want a crisp definition, a practical example from your projects, and awareness of trade-offs—not textbook dumps. Explain a bit more How to structure your answer (60–90 seconds) Define Transacti…
Mid Detailed
Compare two approaches to Indexing—when would you choose each?
Short answer: Interviewers want a crisp definition, a practical example from your projects, and awareness of trade-offs—not textbook dumps. Explain a bit more How to structure your answer (60–90 seconds) Define Indexing…
Junior Detailed
Describe a real-world scenario where Normalization mattered in a PostgreSQL project.
Short answer: Interviewers want a crisp definition, a practical example from your projects, and awareness of trade-offs—not textbook dumps. Explain a bit more How to structure your answer (60–90 seconds) Define Normaliza…
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PostgreSQL Tutorial
Course syllabus

PostgreSQL Tutorial

PostgreSQL — Foundations
PostgreSQL — SQL & Queries
PostgreSQL — Indexing & Performance
PostgreSQL — Transactions & MVCC
PostgreSQL — Functions & Automation
PostgreSQL — JSONB & Modern Features
PostgreSQL — Replication & High Availability
PostgreSQL — Security & Cloud
PostgreSQL — Monitoring & Troubleshooting
PostgreSQL — Real-World Projects
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