Md. Sany Ahmed sany2k8

Search Type	Speed	Accuracy	Flexibility	Storage	Best For
Exact Match	⭐⭐⭐⭐⭐	⭐⭐⭐⭐⭐	⭐	⭐⭐⭐⭐⭐	IDs, codes, filters
Pattern Match	⭐⭐⭐⭐	⭐⭐⭐	⭐⭐⭐	⭐⭐⭐⭐	Autocomplete, prefixes
Full-Text	⭐⭐⭐	⭐⭐⭐⭐	⭐⭐⭐⭐	⭐⭐⭐	Documents, articles
Vector / Semantic	⭐⭐	⭐⭐⭐⭐⭐	⭐⭐⭐⭐⭐	⭐⭐	Recommendations, concepts
Fuzzy	⭐⭐	⭐⭐⭐	⭐⭐⭐⭐	⭐⭐⭐	Typos, data cleaning

Search Type	Additional Storage	Index Size	Notes
Exact Match	None	~2–5% of data	B-tree indexes
Pattern Match	None	~10–20%	GIN trigram indexes
Full-Text	~20–50%	~10–30%	tsvector + GIN index
Vector Search	~50–200%	~20–100%	Depends on dimensions
Fuzzy Search	None	~10–20%	Uses trigram indexes

Types of Analyzers

Analyzer	Description	Example Use
Standard	Default; breaks text by word boundaries, removes most punctuation, lowercases tokens.	English prose, general search
Simple	Splits on non-letter, lowercases.	Part numbers, technical terms
Whitespace	Splits on whitespace only, preserves case.	Code, serial numbers
Keyword	Does not split; treats entire text as a single token.	Exact match fields, IDs, tags

Feature	TF-IDF	BM25
Full Form	Term Frequency – Inverse Document Frequency	Best Matching 25
Default in Elasticsearch	❌ (before v5.0)	✅ (v5.0 and later)
Term Frequency Handling	Linear	Saturated (diminishing returns)
Document Length Normalization	Minimal	Tunable and robust
Tunable Parameters	No	Yes (`k1`, `b`)

Use Case	TF-IDF	BM25
Simple scoring model	✅	✅
Accurate relevance for modern search	❌	✅
Normalize for document length	❌	✅
Tune scoring behavior with parameters	❌	✅

This guide demonstrates the four common types of relationships in SQLAlchemy using realistic examples:

This document demonstrates various PostgreSQL query plan types, with sample datasets, queries, and EXPLAIN/EXPLAIN ANALYZE outputs.

	-- CREATE EXTENSION IF NOT EXISTS postgis;
	-- CREATE EXTENSION IF NOT EXISTS pgvector;

	------------------------------ Exercise 1 ------------------------------
	-- Table setup
	CREATE TABLE products (
	id SERIAL PRIMARY KEY,
	sku VARCHAR(20) UNIQUE,
	name VARCHAR(200),
	category VARCHAR(50),