"symbol">BLCKSZ</code> bytes, typically 8kB.
         The valid range is between
         <code class="literal">0</code>, which disables forced writeback, and
         <code class="literal">2MB</code>.  The default is <code class="literal">512kB</code> on Linux,
         <code class="literal">0</code> elsewhere.  (If <code class="symbol">BLCKSZ</code> is not 8kB,
         the default and maximum values scale proportionally to it.)
         This parameter can only be set in the <code class="filename">postgre