Reword text on ROW SHARE lock as acquired by SELECT FOR

It was missing lock levels FOR KEY SHARE and FOR NO KEY EXCLUSIVE; but
also SELECT FOR UPDATE is not a command separate from SELECT, as the
original text implied.  It is clearer to state that FOR 
is an option of regular SELECT.

Per suggestion from Joey Bodoia 

Reviewed-by: Joey Bodoia  (offlist)
Reviewed-by: Erikjan Rijkers 
Discussion: https://postgr.es/m/164908765512.682.17348032020747341013@wrigleys.postgresql.org

diff --git a/doc/src/sgml/mvcc.sgml b/doc/src/sgml/mvcc.sgml
index 905460723c5b6f5aabea95396dd4542b00ba6369..341fea524a18dd3a64d7c853ed453113967c9f74 100644 (file)
--- a/doc/src/sgml/mvcc.sgml
+++ b/doc/src/sgml/mvcc.sgml
@@ -932,12 +932,14 @@ ERROR:  could not serialize access due to read/write dependencies among transact
         
 
         
-         The SELECT FOR UPDATE and
-         SELECT FOR SHARE commands acquire a
-         lock of this mode on the target table(s) (in addition to
-         ACCESS SHARE locks on any other tables
-         that are referenced but not selected
-         FOR UPDATE/FOR SHARE).
+         The SELECT command acquires a lock of this mode
+         on all tables on which one of the FOR UPDATE,
+         FOR NO KEY UPDATE,
+         FOR SHARE, or
+         FOR KEY SHARE options is specified
+         (in addition to ACCESS SHARE locks on any other
+         tables that are referenced without any explicit
+         FOR ... locking option).