Clearify how processes are started by autovacuum, and what the effect

of autovacuum_max_workers parameter is.

Per discussion with Alvaro.

diff --git a/doc/src/sgml/maintenance.sgml b/doc/src/sgml/maintenance.sgml
index c2a4ce325c0c217e683553a0c5fa148f83b68b78..09c14782d86e0608c1bb090ba41619915ed7c68d 100644 (file)
--- a/doc/src/sgml/maintenance.sgml
+++ b/doc/src/sgml/maintenance.sgml
@@ -1,4 +1,4 @@
-
+
 
 
  Routine Database Maintenance Tasks
@@ -522,10 +522,16 @@ HINT:  Stop the postmaster and use a standalone backend to VACUUM in "mydb".
     The autovacuum daemon actually consists of multiple processes.
     There is a persistent daemon process, called the
     autovacuum launcher, which is in charge of starting
-    an autovacuum worker process on each database every
-     seconds. On each run, the worker
-    process checks each table within that database, and executes
-    VACUUM and/or ANALYZE commands as needed.
+    autovacuum worker processes for all databases. The
+    launcher will distribute the work across time, but attempt to start one
+    worker on each database every 
+    seconds. One worker will be launched for each database, with a maximum
+    of  processes running at the
+    same time. If there are more than
+     databases to be processed,
+    the next database will be processed as soon as the first worker finishes.
+    The worker processes will check each table within its database and
+    execute VACUUM and/or ANALYZE as needed.