index 0d02e21a1ab1101d6ac6933a638e17c305bdd4d1..fea683cb49ce0c17920c48568db43beb2b208cde 100644 (file)
@@ -5068,6 +5068,13 @@ ANY <replaceable class="parameter">num_sync</replaceable> ( <replaceable class="
until it eventually reaches the primary. Standbys make no other use
of feedback they receive other than to pass upstream.
</para>
+ <para>
+ Note that if the clock on standby is moved ahead or backward, the
+ feedback message might not be sent at the required interval. In
+ extreme cases, this can lead to a prolonged risk of not removing dead
+ rows on the primary for extended periods, as the feedback mechanism is
+ based on timestamps.
+ </para>
</listitem>
</varlistentry>