Make the minimum allowed value of work_mem be 64KB always, rather than having

it vary with BLCKSZ as before.  This agrees with what the documentation says,
and avoids a regression test problem when BLCKSZ is larger than default.
Per recent discussion.

doc/src/sgml/config.sgml

-<!-- $PostgreSQL: pgsql/doc/src/sgml/config.sgml,v 1.175 2008/04/18 01:42:17 tgl Exp $ -->
+<!-- $PostgreSQL: pgsql/doc/src/sgml/config.sgml,v 1.176 2008/05/01 19:55:40 tgl Exp $ -->
 
 <chapter Id="runtime-config">
   <title>Server Configuration</title>
@@ -826,7 +826,7 @@ SET ENABLE_SEQSCAN TO OFF;
       <listitem>
        <para>
         Specifies the amount of memory to be used by internal sort operations
-        and hash tables before switching to temporary disk files. The value is
+        and hash tables before switching to temporary disk files. The value
         defaults to one megabyte (<literal>1MB</>).
         Note that for a complex query, several sort or hash operations might be
         running in parallel; each one will be allowed to use as much memory

src/backend/utils/misc/guc.c

@@ -10,7 +10,7 @@
  * Written by Peter Eisentraut <peter_e@gmx.net>.
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/utils/misc/guc.c,v 1.449 2008/04/29 20:44:49 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/backend/utils/misc/guc.c,v 1.450 2008/05/01 19:55:40 tgl Exp $
  *
  *--------------------------------------------------------------------
  */
@@ -1339,7 +1339,7 @@ static struct config_int ConfigureNamesInt[] =
 			GUC_UNIT_KB
 		},
 		&work_mem,
-		1024, 8 * BLCKSZ / 1024, MAX_KILOBYTES, NULL, NULL
+		1024, 64, MAX_KILOBYTES, NULL, NULL
 	},
 
 	{