codesnips

explain

sql 
-- EXPLAIN ANALYZE (actual execution statistics)
EXPLAIN ANALYZE
SELECT u.username, COUNT(o.id) AS order_count
FROM users u
LEFT JOIN orders o ON u.id = o.user_id
WHERE u.created_at >= '2024-01-01'

Advanced query optimization techniques

database optimization query-performance
by Maria Garcia 2 tabs
ruby 
class ExplainAnalyzer
  def initialize(relation, watched_tables:)
    @relation = relation
    @watched_tables = Array(watched_tables).map(&:to_s)
  end

Fast Fail for Missing Indexes (EXPLAIN sanity check)

rails postgres performance
by codesnips 3 tabs
sql 
-- Basic EXPLAIN
EXPLAIN
SELECT * FROM users WHERE email = 'alice@example.com';

-- EXPLAIN with cost and row estimates
-- Output shows: Seq Scan on users (cost=0.00..15.50 rows=1 width=100)

EXPLAIN and query plan optimization

sql explain query-optimization
by Maria Garcia 2 tabs
sql 
CREATE TABLE subscriptions (
    id                  BIGGENERATED ALWAYS AS IDENTITY PRIMARY KEY,
    customer_id         BIGINT       NOT NULL,
    plan_code           TEXT         NOT NULL,
    status              TEXT         NOT NULL DEFAULT 'active',
    current_period_end  TIMESTAMPTZ  NOT NULL,

Partial index for “active” rows in Postgres

postgres performance sql
by codesnips 3 tabs