diff --git a/doc/src/sgml/config.sgml b/doc/src/sgml/config.sgml
index 7311169bdd..42877654cd 100644
--- a/doc/src/sgml/config.sgml
+++ b/doc/src/sgml/config.sgml
@@ -1697,9 +1697,10 @@ include_dir 'conf.d'
(such as a sort or hash table) before writing to temporary disk files.
If this value is specified without units, it is taken as kilobytes.
The default value is four megabytes (4MB).
- Note that for a complex query, several sort or hash operations might be
- running in parallel; each operation will be allowed to use as much memory
- as this value specifies before it starts to write data into temporary
+ Note that a complex query might perform several sort and hash
+ operations at the same time, with each operation generally being
+ allowed to use as much memory as this value specifies before it
+ starts to write data into temporary
files. Also, several running sessions could be doing such operations
concurrently. Therefore, the total memory used could be many
times the value of work_mem; it is necessary to