Add note that TRUNCATE uses an access exclusive lock. This apparently

surprised/confused some users.

diff --git a/doc/src/sgml/ref/truncate.sgml b/doc/src/sgml/ref/truncate.sgml
index 03a66859082fcbf40aec2739630c724899779d50..d765c1bd8c72a873e14e14c598ed86d2c48104ff 100644 (file)
--- a/doc/src/sgml/ref/truncate.sgml
+++ b/doc/src/sgml/ref/truncate.sgml
@@ -1,5 +1,5 @@
 
 
@@ -102,6 +102,13 @@ TRUNCATE [ TABLE ] name [, ... ]
    to truncate it.
   
 
+  
+   TRUNCATE acquires an access exclusive lock on the
+   tables in operates on, which blocks all other concurrent operations
+   on the table.  If concurrent access to a table is required, then
+   the DELETE command should be used instead.
+  
+
   
    TRUNCATE cannot be used on a table that has foreign-key
    references from other tables, unless all such tables are also truncated