title: PostgreSQL 12 - large cache files in "base" directory
body: <p>I have noticed that my small 8MB database is cached by PostgreSQL 12 in this folder:</p>
  <pre><code>/var/lib/postgresql/12/main/base/16384
  </code></pre>
  <p>This folder contains multiple 1GB files for example &quot;16417&quot; that weighs 1073741824 bytes.</p>
  <p>How to remove these files and limit cache file space to max 100 GB? Now it uses as much space as it can and crashes my disk (no space left).</p>
  <p>In postgresql.conf file i have changed these options:</p>
  <pre><code>temp_file_limit = 10000000 
  shared_buffers = 128MB 
  checkpoint_timeout = 12h
  max_wal_size = 100MB
  min_wal_size = 80MB
  </code></pre>
  <p>but unfortunately it did not help.</p>
  <p>What else can I do to resolve this issue? In one our these files grew up to 80 GB...</p>
  <p>EDIT: This issue occurs even with default settings. My system is Ubuntu 18.04.4.</p>