PostgreSQL

CREATE INDEX idx_users_email ON users(email);
EXPLAIN ANALYZE SELECT * FROM users WHERE email = '[email protected]';

EXPLAIN ANALYZE
SELECT *
FROM users
WHERE email = '[email protected]';

INSERT INTO users(email, name)
VALUES ('[email protected]', 'Ada')
ON CONFLICT (email)
DO UPDATE SET name = EXCLUDED.name;

CREATE INDEX idx_events_payload ON events USING GIN (payload);

-- example query (jsonb contains)
SELECT * FROM events WHERE payload @> '{"type":"click"}';

CREATE INDEX idx_users_active_email
ON users (email)
WHERE active = true AND deleted_at IS NULL;

SELECT user_id,
       created_at,
       ROW_NUMBER() OVER (PARTITION BY user_id ORDER BY created_at DESC) AS rn
FROM logins;

COPY users(email, created_at)
FROM STDIN WITH (FORMAT csv, HEADER true);