Restructure autovacuum in two processes: a dummy process, which runs

continuously, and requests vacuum runs of "autovacuum workers" to postmaster.
The workers do the actual vacuum work.  This allows for future improvements,
like allowing multiple autovacuum jobs running in parallel.

For now, the code keeps the original behavior of having a single autovac
process at any time by sleeping until the previous worker has finished.

1 files changed, 3 insertions, 2 deletions

diff --git a/src/include/storage/pmsignal.h b/src/include/storage/pmsignal.h
index bc705fc1362..8142ee0f2c4 100644
--- a/src/include/storage/pmsignal.h
+++ b/src/include/storage/pmsignal.h
@@ -7,7 +7,7 @@
  * Portions Copyright (c) 1996-2007, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $PostgreSQL: pgsql/src/include/storage/pmsignal.h,v 1.16 2007/01/05 22:19:58 momjian Exp $
+ * $PostgreSQL: pgsql/src/include/storage/pmsignal.h,v 1.17 2007/02/15 23:23:23 alvherre Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -26,7 +26,8 @@ typedef enum
 	PMSIGNAL_WAKEN_CHILDREN,	/* send a SIGUSR1 signal to all backends */
 	PMSIGNAL_WAKEN_ARCHIVER,	/* send a NOTIFY signal to xlog archiver */
 	PMSIGNAL_ROTATE_LOGFILE,	/* send SIGUSR1 to syslogger to rotate logfile */
-	PMSIGNAL_START_AUTOVAC,		/* start an autovacuum iteration */
+	PMSIGNAL_START_AUTOVAC_LAUNCHER, /* start an autovacuum launcher */
+	PMSIGNAL_START_AUTOVAC_WORKER, /* start an autovacuum worker */
 
 	NUM_PMSIGNALS				/* Must be last value of enum! */
 } PMSignalReason;