Update of /home/cvsd/slony1/slony1-engine/doc/adminguide
In directory main.slony.info:/tmp/cvs-serv26870

Modified Files:
	slonyupgrade.sgml 
Log Message:
Add to upgrade-to-2.0 docs another approach to handling tables with
columns defined via TABLE ADD KEY.


Index: slonyupgrade.sgml
===================================================================
RCS file: /home/cvsd/slony1/slony1-engine/doc/adminguide/slonyupgrade.sgml,v
retrieving revision 1.6
retrieving revision 1.7
diff -C2 -d -r1.6 -r1.7
*** slonyupgrade.sgml	18 Apr 2007 15:03:51 -0000	1.6
--- slonyupgrade.sgml	9 Jul 2007 15:19:49 -0000	1.7
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*** 113,121 ****
  command <xref linkend="stmtsetdroptable">. </para>
  
! <para> This does <emphasis>not</emphasis> drop out the &slony1;-generated column. </para>
! 
  </listitem>
! <listitem><para> On each node, run an SQL script to alter the table, dropping the extra column.</para> 
! <para> <command> alter table whatever drop column "_Slony-I_cluster-rowID";</command> </para>
  
  <para> This needs to be run individually against each node.  Depending
--- 113,123 ----
  command <xref linkend="stmtsetdroptable">. </para>
  
! <para> This does <emphasis>not</emphasis> drop out the
! &slony1;-generated column. </para>
  </listitem>
! 
! <listitem><para> On each node, run an SQL script to alter the table,
! dropping the extra column.</para> <para> <command> alter table
! whatever drop column "_Slony-I_cluster-rowID";</command> </para>
  
  <para> This needs to be run individually against each node.  Depending
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*** 190,193 ****
--- 192,240 ----
  
  </itemizedlist>
+ 
+ <para> This approach should be fine for tables that are relatively
+ small, or infrequently used.  If, on the other hand, the table is
+ large and heavily used, another approach may prove necessary, namely
+ to create your own sequence, and <quote>promote</quote> the formerly
+ &slony1;-generated column into a <quote>real</quote> column in your
+ database schema.  An outline of the steps is as follows: </para>
+ 
+ <itemizedlist>
+ 
+ <listitem><para> Add a sequence that assigns values to the
+ column. </para>
+ 
+ <para> Setup steps will include SQL <command>CREATE
+ SEQUENCE</command>, SQL <command>SELECT SETVAL()</command> (to set the
+ value of the sequence high enough to reflect values used in the
+ table), Slonik <xref linkend="stmtcreateset"> (to create a set to
+ assign the sequence to), Slonik <xref linkend="stmtsetaddsequence">
+ (to assign the sequence to the set), Slonik <xref
+ linkend="stmtsubscribeset"> (to set up subscriptions to the new
+ set)</para>
+ </listitem>
+ 
+ <listitem><para> Attach the sequence to the column on the
+ table. </para>
+ 
+ <para> This involves <command>ALTER TABLE ALTER COLUMN</command>,
+ which must be submitted via the Slonik command <xref
+ linkend="stmtddlscript">. </para>
+ </listitem>
+ 
+ <listitem><para> Rename the column
+ <envar>_Slony-I_ at CLUSTERNAME@_rowID</envar> so that &slony1; won't
+ consider it to be under its control.</para>
+ 
+ <para> This involves <command>ALTER TABLE ALTER COLUMN</command>,
+ which must be submitted via the Slonik command <xref
+ linkend="stmtddlscript">. </para>
+ 
+ <para> Note that these two alterations might be accomplished via the
+ same <xref linkend="stmtddlscript"> request. </para>
+ </listitem>
+ 
+ </itemizedlist>
+ 
  </sect2>
  </sect1>