Search Engine & Full-Text Retrieval Expert (2026 Edition)

English | Bahasa Indonesia

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<a name="english"></a>

English

Description

Production guide for high-performance search engines, typo-tolerant autocomplete, faceted navigation, and hybrid retrieval. Covers native PostgreSQL Full-Text Search (tsvector, GIN index, pg_trgm), dedicated search engines (Typesense, Meilisearch), enterprise distributed clusters (OpenSearch/Elasticsearch), and hybrid search using Reciprocal Rank Fusion (RRF) to merge keyword matching with semantic vector embeddings.

Trigger Conditions

• Implementing instant autocomplete or search-as-you-type beyond simple SQL LIKE %query% filters.
• Setting up faceted e-commerce product navigation (filtering by category, price ranges, ratings).
• Choosing between PostgreSQL built-in FTS vs dedicated clusters (Typesense/Meilisearch).
• Achieving sub-50ms search latency across millions of records.
• Implementing hybrid search combining dense vectors with sparse BM25 / full-text scores.

Level 1: Native PostgreSQL Full-Text Search (Zero Extra Infrastructure)

-- Enable trigram extension for typo tolerance and fuzzy matching
CREATE EXTENSION IF NOT EXISTS pg_trgm;

-- Create articles table with an automated tsvector generated column
CREATE TABLE IF NOT EXISTS articles (
  id UUID PRIMARY KEY DEFAULT gen_random_uuid(),
  title VARCHAR(255) NOT NULL,
  content TEXT NOT NULL,
  category VARCHAR(64) NOT NULL,
  search_tokens TSVECTOR GENERATED ALWAYS AS (
    setweight(to_tsvector('english', coalesce(title, '')), 'A') ||
    setweight(to_tsvector('english', coalesce(content, '')), 'B')
  ) STORED
);

-- Crucial: GIN index for full-text queries & Trigram index for typos
CREATE INDEX IF NOT EXISTS idx_articles_fts ON articles USING GIN (search_tokens);
CREATE INDEX IF NOT EXISTS idx_articles_title_trgm ON articles USING GIN (title gin_trgm_ops);

-- Fast ranked query with typo fallback
SELECT 
  id, 
  title, 
  ts_rank_cd(search_tokens, websearch_to_tsquery('english', :query)) AS rank,
  similarity(title, :query) AS sim_score
FROM articles
WHERE search_tokens @@ websearch_to_tsquery('english', :query)
   OR title % :query
ORDER BY rank DESC, sim_score DESC
LIMIT 20;

Level 2: Dedicated Typo-Tolerant Engine (Typesense 2026)

// src/lib/search/typesense-client.ts
import Typesense from 'typesense';

export const typesenseClient = new Typesense.Client({
  nodes: [{ host: process.env.TYPESENSE_HOST || 'localhost', port: 8108, protocol: 'http' }],
  apiKey: process.env.TYPESENSE_API_KEY!,
  connectionTimeoutSeconds: 2,
});

export async function searchProducts(searchTerm: string, selectedCategory?: string, maxPrice?: number) {
  const filterConditions: string[] = [];
  if (selectedCategory) filterConditions.push(`category:=${selectedCategory}`);
  if (maxPrice) filterConditions.push(`price:<=${maxPrice}`);

  const searchParams = {
    q: searchTerm || '*',
    query_by: 'name,description,brand',
    query_by_weights: '3,2,1',
    filter_by: filterConditions.join(' && '),
    facet_by: 'category,brand,price',
    sort_by: '_text_match:desc,rating:desc',
    num_typos: 2,
    per_page: 24,
  };

  const results = await typesenseClient.collections('products').documents().search(searchParams);
  return {
    hits: results.hits?.map((h: any) => h.document) || [],
    facets: results.facet_counts || [],
    found: results.found,
  };
}

Reciprocal Rank Fusion (RRF) Hybrid Formula

When blending keyword search with vector semantic search, apply RRF to avoid score calibration drift: $$\text{RRF Score}(d) = \sum_{m \in M} \frac{1}{60 + r_m(d)}$$ Where $r_m(d)$ is the 1-based rank of document $d$ in system $m$ (BM25 or Dense Vector).

Orchestration & Integration

• database-orm-expert: Maintains PostgreSQL generated tsvector columns in Drizzle/Prisma.
• vector-db-rag-expert: Powers the dense vector half of hybrid search.
• ecommerce-expert: Drives product catalog search, autocomplete, and facet filters.
• performance-web-vitals: Ensures search autocomplete debouncing (<150ms) to prevent INP regression.

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<a name="bahasa-indonesia"></a>

Bahasa Indonesia

Deskripsi

Panduan produksi untuk mesin pencarian berkecepatan tinggi, autocomplete toleran salah ketik (typo-tolerant), navigasi berfaset (faceted search), dan pencarian hibrida (hybrid search). Mencakup Full-Text Search bawaan PostgreSQL (tsvector, GIN index, pg_trgm), mesin pencari khusus (Typesense, Meilisearch), kluster enterprise (OpenSearch/Elasticsearch), serta penggabungan skor kata kunci dan vektor semantik menggunakan formula Reciprocal Rank Fusion (RRF).

Kondisi Pemicu

• Mengimplementasikan pencarian instan dan autocomplete di luar query dasar SQL LIKE %kata%.
• Membangun filter produk e-commerce berdasarkan kategori, kisaran harga, dan rating.
• Memilih antara FTS native PostgreSQL vs mesin pencari terdedikasi (Typesense/Meilisearch).
• Menargetkan latensi pencarian di bawah 50 milidetik pada jutaan baris data.
• Menggabungkan pencarian teks biasa dengan pencarian semantik AI (Hybrid Search).

Pola Integrasi Pencarian Instan di Next.js

// src/app/api/search/route.ts
import { NextResponse } from 'next/server';
import { searchProducts } from '@/lib/search/typesense-client';

export async function GET(request: Request) {
  const { searchParams } = new URL(request.url);
  const q = searchParams.get('q') || '';
  const category = searchParams.get('category') || undefined;
  const maxPrice = searchParams.get('maxPrice') ? parseFloat(searchParams.get('maxPrice')!) : undefined;

  try {
    const data = await searchProducts(q, category, maxPrice);
    return NextResponse.json(data);
  } catch (error) {
    return NextResponse.json({ error: 'Gagal melakukan pencarian' }, { status: 500 });
  }
}

Kapan Menggunakan PostgreSQL vs Typesense?

• Gunakan PostgreSQL FTS: Jika data di bawah 1 juta baris dan Anda ingin menghindari biaya/kompleksitas infrastruktur tambahan.
• Gunakan Typesense / Meilisearch: Jika membutuhkan koreksi saltik otomatis yang instan (instant typo-tolerance), pencarian saat mengetik (search-as-you-type <10ms), dan filter faset kompleks tanpa membebani database utama.

Integrasi Orkestrasi

• database-orm-expert: Sinkronisasi data antara PostgreSQL dengan index Typesense melalui webhook atau event outbox.
• vector-db-rag-expert: Menyediakan ranking semantik untuk pencarian hibrida.
• ecommerce-expert: Menghubungkan faset pencarian dengan katalog produk toko online.
• performance-web-vitals: Mencegah pemanggilan API berlebihan dengan teknik debounce 150-200ms pada input pencarian.