postgresql/src/backend/storage/ipc
Alvaro Herrera 1820650934 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.
2007-02-15 23:23:23 +00:00
..
ipc.c Update CVS HEAD for 2007 copyright. Back branches are typically not 2007-01-05 22:20:05 +00:00
ipci.c Restructure autovacuum in two processes: a dummy process, which runs 2007-02-15 23:23:23 +00:00
Makefile Remove remains of old depend target. 2007-01-20 17:16:17 +00:00
pmsignal.c Update CVS HEAD for 2007 copyright. Back branches are typically not 2007-01-05 22:20:05 +00:00
procarray.c Arrange for autovacuum to be killed when another operation wants to be alone 2007-01-16 13:28:57 +00:00
README $Header: -> $PostgreSQL Changes ... 2003-11-29 19:52:15 +00:00
shmem.c Update CVS HEAD for 2007 copyright. Back branches are typically not 2007-01-05 22:20:05 +00:00
shmqueue.c Update CVS HEAD for 2007 copyright. Back branches are typically not 2007-01-05 22:20:05 +00:00
sinval.c Update CVS HEAD for 2007 copyright. Back branches are typically not 2007-01-05 22:20:05 +00:00
sinvaladt.c Update CVS HEAD for 2007 copyright. Back branches are typically not 2007-01-05 22:20:05 +00:00

$PostgreSQL: pgsql/src/backend/storage/ipc/README,v 1.4 2003/11/29 19:51:56 pgsql Exp $
Mon Jul 18 11:09:22 PDT 1988  W.KLAS

Cache invalidation synchronization routines:
===========================================

The cache synchronization is done using a message queue. Every
backend can register a message which then has to be read by
all backends. A message read by all backends is removed from the 
queue automatically. If a message has been lost because the buffer
was full, all backends that haven't read this message will be
told that they have to reset their cache state. This is done
at the time when they try to read the message queue.

The message queue is implemented as a shared buffer segment. Actually,
the queue is a circle to allow fast inserting, reading (invalidate data) and
maintaining the buffer.