Modify parallel pg_restore to track pending and ready items by means of

two new lists, rather than repeatedly rescanning the main TOC list.
This avoids a potential O(N^2) slowdown, although you'd need a *lot*
of tables to make that really significant; and it might simplify future
improvements in the scheduling algorithm by making the set of ready
items more easily inspectable.  The original thought that it would
in itself result in a more efficient job dispatch order doesn't seem
to have been borne out in testing, but it seems worth doing anyway.

src/bin/pg_dump/pg_backup_archiver.h

@@ -17,7 +17,7 @@
  *
  *
  * IDENTIFICATION
- *		$PostgreSQL: pgsql/src/bin/pg_dump/pg_backup_archiver.h,v 1.81 2009/08/04 21:56:09 tgl Exp $
+ *		$PostgreSQL: pgsql/src/bin/pg_dump/pg_backup_archiver.h,v 1.82 2009/08/07 22:48:34 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -314,7 +314,8 @@ typedef struct _tocEntry
 	void	   *formatData;		/* TOC Entry data specific to file format */
 
 	/* working state (needed only for parallel restore) */
-	bool		restored;		/* item is in progress or done */
+	struct _tocEntry *par_prev;	/* list links for pending/ready items; */
+	struct _tocEntry *par_next;	/* these are NULL if not in either list */
 	bool		created;		/* set for DATA member if TABLE was created */
 	int			depCount;		/* number of dependencies not yet restored */
 	DumpId	   *lockDeps;		/* dumpIds of objects this one needs lock on */