title: H2 postgresql mode seems not working for me
body: <p>My application accesses Postgres database and I have many predefined queries (Rank, Partition, complex join etc) I fire against Postgres. Now I want to go for unit testing these queries behaviour with small test data.</p>
  <p>So I started with H2/JUnit. I found out that most of Postgres queries like Rank, Partition, Complex case when update etc. So I thought of using H2 PosgreSQL compatibility mode - will all Postgres queries work on H2?</p>
  <p>I followed H2 documentation saying:</p>
  <blockquote>
  <p>To use the PostgreSQL mode, use the database URL jdbc:h2:~/test;MODE=PostgreSQL or the SQL statement SET MODE PostgreSQL.</p>
  </blockquote>
  <p>I enabled mode using <code>SET MODE PostgreSQL</code> and I tried to fire one of the query which involves <code>rank()</code> and works in Postgres but it did not work H2. It gives me the following exception:</p>
  <pre><code>Function &quot;RANK' not found; in SQL statement
  </code></pre>
  <p>I am new to H2 and database testing. I am using H2 JDBC driver to fire Postgres queries by thinking H2 Posgress compatibility mode will allow me to fire Postgres queries.</p>