Clarify what commands are not allowed in SQL functions.

diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml
index c65f8522b37519c9ba6b2ea9a18b702ca59a57dd..70dfe380190281662daca21b2ca5e7206829f4ab 100644 (file)
--- a/doc/src/sgml/xfunc.sgml
+++ b/doc/src/sgml/xfunc.sgml
@@ -116,9 +116,9 @@
      Besides SELECT queries, the commands can include data
      modification queries (INSERT,
      UPDATE, and DELETE), as well as
-     other SQL commands. (The only exception is that you cannot put
-     BEGIN, COMMIT, ROLLBACK, or
-     SAVEPOINT commands into a SQL function.)
+     other SQL commands. (You cannot put transaction commands, e.g.
+     COMMIT, SAVEPOINT, and some utility
+     commands, e.g.  VACUUM, into an SQL function.)
      However, the final command
      must be a SELECT or have a RETURNING
      clause that returns whatever is