How to fix Too many columns in PostgreSQL

SELECT COUNT(*) as column_count
FROM information_schema.columns
WHERE table_schema = 'public' AND table_name = 'your_table_name';

-- Before (too wide)
CREATE TABLE users (
  id INT,
  name TEXT,
  prop_1 TEXT, prop_2 TEXT, ... -- 1,500+ properties
);

-- After (normalized)
CREATE TABLE users (id INT PRIMARY KEY, name TEXT);
CREATE TABLE user_properties (
  id INT PRIMARY KEY,
  user_id INT REFERENCES users(id),
  key TEXT,
  value TEXT
);

CREATE TABLE products (
  id INT PRIMARY KEY,
  name TEXT,
  metadata JSONB  -- stores hundreds of optional attributes
);

INSERT INTO products VALUES (1, 'Widget', '{"color": "red", "weight": 2.5, "tags": ["sale", "new"]}'::jsonb);
SELECT metadata->'color' FROM products WHERE id = 1;

CREATE TABLE contacts (
  id INT PRIMARY KEY,
  name TEXT,
  phone_numbers TEXT[],  -- can store 100+ numbers in one column
  addresses TEXT[]
);

INSERT INTO contacts VALUES (1, 'Alice', ARRAY['555-1234', '555-5678'], ARRAY['123 Main St']);
SELECT phone_numbers[1] FROM contacts WHERE id = 1;

-- Instead of this:
SELECT * FROM view_a 
JOIN view_b ON view_a.id = view_b.id;  -- ERROR: too many columns

-- Do this:
SELECT view_a.id, view_a.name, view_b.description
FROM view_a 
JOIN view_b ON view_a.id = view_b.id;

-- Dump schema and data
pg_dump -t your_table_name your_db > table.sql

-- Create new table (ideally redesigned)
DROP TABLE your_table_name CASCADE;

-- Restore from dump or insert redesigned data
psql -d your_db < table.sql