title: Connection Pooling with PostgreSQL JDBC
body: <p>Recently I downloaded the JDBC driver for PostgreSQL from <a href="https://jdbc.postgresql.org/download.html" rel="noreferrer">here</a>.
  Since I'm using Java 1.7 JVM and it's written:</p>
  
  <blockquote>
    <p>If you are using the 1.6 or 1.7 JVM, then you should use the JDBC4
    version.</p>
  </blockquote>
  
  <p>I download JDBC4. The problem is there exist no <code>PoolingDataSource's</code> in it.
  If you get JDBC3 you can use <code>org.postgresql.jdbc3.Jdbc3PoolingDataSource</code> or
  others as is seen <a href="https://www.postgresql.org/docs/7.3/static/jdbc-datasource.html#org.postgresql.jdbc3.Jdbc3PoolingDataSource" rel="noreferrer">here</a>.</p>
  
  <p>Is there any pooling <code>DataSource</code> in JDBC4 that I don't know about, or what should
  I use instead? The only thing I found in JDBC4 is <a href="https://jdbc.postgresql.org/documentation/publicapi/org/postgresql/ds/PGPoolingDataSource.html" rel="noreferrer"><code>PGPoolingDataSource</code></a> but I'm not
  sure if I'm supposed to use this because based on their Java doc message:</p>
  
  <blockquote>
    <p>Don't use this if your server/middleware vendor provides a connection pooling implementation which interfaces with the PostgreSQL ConnectionPoolDataSource implementation!</p>
  </blockquote>