@@ -658,6 +658,26 @@ ERROR: could not serialize access due to read/write dependencies among transact
658658 protections automatically provided by Serializable transactions.
659659 </para>
660660 </listitem>
661+ <listitem>
662+ <para>
663+ When the system is forced to combine multiple page-level predicate
664+ locks into a single relation-level predicate lock because the predicate
665+ lock table is short of memory, an increase in the rate of serialization
666+ failures may occur. You can avoid this by increasing
667+ <xref linkend="guc-max-pred-locks-per-transaction">.
668+ </para>
669+ </listitem>
670+ <listitem>
671+ <para>
672+ A sequential scan will always necessitate a relation-level predicate
673+ lock. This can result in an increased rate of serialization failures.
674+ It may be helpful to encourage the use of index scans by reducing
675+ <xref linkend="guc-random-page-cost"> and/or increasing
676+ <xref linkend="guc-cpu-tuple-cost">. Be sure to weigh any decrease
677+ in transaction rollbacks and restarts against any overall change in
678+ query execution time.
679+ </para>
680+ </listitem>
661681 </itemizedlist>
662682 </para>
663683