title: How in Logstash update index with new data?
body: <p>I have <code>PostgreSQL 10</code> database with table. 7000 new data comes into the table every hour.</p>
  
  <p>In <code>Logstash 6.4</code> I have such <code>.conf</code> file which create index in <code>Elasticsearch</code>.</p>
  
  <p><code>.conf</code>:</p>
  
  <pre><code>input {
      jdbc {
          jdbc_connection_string =&gt; "jdbc:postgresql://@host:@port/@database"
          jdbc_user =&gt; "@username"
          jdbc_password =&gt; "@password"
          jdbc_driver_library =&gt; "C:\postgresql-42.2.5.jar"
          jdbc_driver_class =&gt; "org.postgresql.Driver"
          statement =&gt; "SELECT * from table_name"
      }
  }
  output {
      elasticsearch {
          hosts =&gt; ["localhost:9200"]
          index =&gt; "table_name"
      }
  }
  </code></pre>
  
  <p><strong>Questions</strong>:</p>
  
  <ol>
  <li>How update existing index with new data which appeared in table?</li>
  <li>What is the maximum amount of data index can store? Could there be an overflow?</li>
  </ol>