Add note pointing out that read-only commands no longer consume

command IDs.

diff --git a/doc/src/sgml/ddl.sgml b/doc/src/sgml/ddl.sgml
index de06bbe359e88d245503e217c7fd1631e627508a..98233866300c6e3c50d1d16e310f2c842d7bd03a 100644 (file)
--- a/doc/src/sgml/ddl.sgml
+++ b/doc/src/sgml/ddl.sgml
@@ -1,4 +1,4 @@
-
+
 
 
  Data Definition
@@ -1034,12 +1034,14 @@ CREATE TABLE order_items (
    
 
    
-    Command
-    identifiers are also 32-bit quantities.  This creates a hard limit
+    Command identifiers are also 32-bit quantities.  This creates a hard limit
     of 232 (4 billion) SQL commands
     within a single transaction.  In practice this limit is not a
     problem — note that the limit is on number of
     SQL commands, not number of rows processed.
+    Also, as of PostgreSQL 8.3, only commands
+    that actually modify the database contents will consume a command
+    identifier.