title: PostgreSQL Transaction Isolation READ UNCOMMITTED
body: <p>I want to try transaction isolation using PostgreSQL with pgadmin. First I inserted a new record inside BEGIN but without COMMIT.</p>
  
  <pre><code>BEGIN;
  INSERT INTO my_table(id,value) VALUES (1,'something');
  
  //UNCOMMITTED
  </code></pre>
  
  <p>Then, I tried to read the uncommitted data</p>
  
  <pre><code>BEGIN TRANSACTION ISOLATION LEVEL READ UNCOMMITTED;
  SELECT * FROM my_table
  COMMIT;
  </code></pre>
  
  <p>But I couldn't find the new record. What's wrong?</p>