Code review for ON COMMIT patch. Make the actual on-commit action happen

before commit, not after :-( --- the original coding is not only unsafe
if an error occurs while it's processing, but it generates an invalid
sequence of WAL entries.  Resurrect 7.2 logic for deleting items when
no longer needed.  Use an enum instead of random macros.  Editorialize
on names used for routines and constants.  Teach backend/nodes routines
about new field in CreateTable struct.  Add a regression test.

1 files changed, 14 insertions, 16 deletions

diff --git a/doc/src/sgml/ref/create_table.sgml b/doc/src/sgml/ref/create_table.sgml
index 274b6f8c518..4907789b272 100644
--- a/doc/src/sgml/ref/create_table.sgml
+++ b/doc/src/sgml/ref/create_table.sgml
@@ -1,5 +1,5 @@
 <!--
-$Header: /cvsroot/pgsql/doc/src/sgml/ref/create_table.sgml,v 1.57 2002/11/09 23:56:38 momjian Exp $
+$Header: /cvsroot/pgsql/doc/src/sgml/ref/create_table.sgml,v 1.58 2002/11/11 22:19:20 tgl Exp $
 PostgreSQL documentation
 -->
 
@@ -21,7 +21,8 @@ CREATE [ [ LOCAL ] { TEMPORARY | TEMP } ] TABLE <replaceable class="PARAMETER">t
     | <replaceable>table_constraint</replaceable> }  [, ... ]
 )
 [ INHERITS ( <replaceable>parent_table</replaceable> [, ... ] ) ]
-[ WITH OIDS | WITHOUT OIDS ] [ON COMMIT { PRESERVE ROWS | DELETE ROWS | DROP } ]
+[ WITH OIDS | WITHOUT OIDS ]
+[ ON COMMIT { PRESERVE ROWS | DELETE ROWS | DROP } ]
 
 where <replaceable class="PARAMETER">column_constraint</replaceable> is:
 
@@ -107,8 +108,8 @@ and <replaceable class="PARAMETER">table_constraint</replaceable> is:
      <para>
       If specified, the table is created as a temporary table.
       Temporary tables are automatically dropped at the end of a
-      session or optionally at the end of the current transaction 
-      (See ON COMMIT below).  Existing permanent tables with the same 
+      session, or optionally at the end of the current transaction 
+      (see ON COMMIT below).  Existing permanent tables with the same 
       name are not visible to the current session while the temporary 
       table exists, unless they are referenced with schema-qualified 
       names. Any indexes created on a temporary table are automatically
@@ -493,22 +494,17 @@ and <replaceable class="PARAMETER">table_constraint</replaceable> is:
     <term><literal>ON COMMIT</literal></term>
     <listitem>
      <para>
-      The behaviour of temporary tables at the end of a transaction
+      The behavior of temporary tables at the end of a transaction
       block can be controlled using <literal>ON COMMIT</literal>. 
-      The table will exhibit the same behavior at the end of
-      transaction blocks for the duration of the session unless
-      ON COMMIT DROP is specified or the temporary table is dropped.
-     </para>
-     <para>
-      The three parameters to ON COMMIT are:
+      The three options are:
 
       <variablelist>
        <varlistentry>
         <term><literal>PRESERVE ROWS</literal></term>
         <listitem>
          <para>
-          The rows in the temporary table will persist after the
-          transaction block.
+	  No special action is taken at the ends of transactions.
+	  This is the default behavior.
          </para>
      	</listitem>
        </varlistentry>
@@ -517,8 +513,9 @@ and <replaceable class="PARAMETER">table_constraint</replaceable> is:
         <term><literal>DELETE ROWS</literal></term>
         <listitem>
          <para>
-          All rows in the temporary table will be deleted at the 
-          end of the transaction block.
+          All rows in the temporary table will be deleted at the
+          end of each transaction block.  Essentially, an automatic
+	  <xref linkend="sql-truncate"> is done at each commit.
          </para>
         </listitem>
        </varlistentry>
@@ -527,7 +524,8 @@ and <replaceable class="PARAMETER">table_constraint</replaceable> is:
         <term><literal>DROP</literal></term>
         <listitem>
          <para>
-          The temporary table will be dropped at the end of the transaction.
+          The temporary table will be dropped at the end of the current
+	  transaction block.
          </para>
         </listitem>
        </varlistentry>