I attach a little patch to make CLUSTER set and reset the indisclustered

bit on the indexes.

I also attach clusterdb and clusterdb.sgml; both of them are blatant
rips of vacuumdb and vacuumdb.sgml, but get the job done.  Please review
them, as I'm probably making a lot of mistakes with SGML and I can't
compile it here.

vacuumdb itself is not very comfortable to use when the databases have
passwords, because it has to connect once for each table (I can probably
make it connect only once for each database; should I?).  Because of
this I added a mention of PGPASSWORDFILE in the documentation, but I
don't know if that is the correct place for that.

Alvaro Herrera

src/test/regress/expected/cluster.out

@@ -274,3 +274,14 @@ FROM pg_class c WHERE relname LIKE 'clstr_tst%' ORDER BY relname;
  clstr_tst_s_rf_a_seq | S       | f
 (11 rows)
 
+-- Verify that indisclustered is correctly set
+SELECT pg_class.relname FROM pg_index, pg_class, pg_class AS pg_class_2
+WHERE pg_class.oid=indexrelid
+	AND indrelid=pg_class_2.oid
+	AND pg_class_2.relname = 'clstr_tst'
+	AND indisclustered;
+   relname   
+-------------
+ clstr_tst_c
+(1 row)
+

src/test/regress/sql/cluster.sql

@@ -79,3 +79,10 @@ SELECT conname FROM pg_constraint WHERE conrelid = 'clstr_tst'::regclass;
 SELECT relname, relkind,
     EXISTS(SELECT 1 FROM pg_class WHERE oid = c.reltoastrelid) AS hastoast
 FROM pg_class c WHERE relname LIKE 'clstr_tst%' ORDER BY relname;
+
+-- Verify that indisclustered is correctly set
+SELECT pg_class.relname FROM pg_index, pg_class, pg_class AS pg_class_2
+WHERE pg_class.oid=indexrelid
+	AND indrelid=pg_class_2.oid
+	AND pg_class_2.relname = 'clstr_tst'
+	AND indisclustered;