Thread: Why do we need pg_vlock?

It seems to me there's no fundamental reason why there couldn't be
two VACUUMs running concurrently in a database.  With the locking
we are doing now, it should be safe enough.  So, I'd like to propose
that we get rid of the pg_vlock lock file.  It doesn't have any useful
purpose but it does force manual intervention by the dbadmin to recover
if a VACUUM crashes :-(

Comments?  Did I miss something about why we can't have more than one
vacuum process?
        regards, tom lane

> It seems to me there's no fundamental reason why there couldn't be
> two VACUUMs running concurrently in a database.  With the locking
> we are doing now, it should be safe enough.  So, I'd like to propose
> that we get rid of the pg_vlock lock file.  It doesn't have any useful
> purpose but it does force manual intervention by the dbadmin to recover
> if a VACUUM crashes :-(
> 
> Comments?  Did I miss something about why we can't have more than one
> vacuum process?

I vote for removal.  Lock files are hacks, usually.

--  Bruce Momjian                        |  http://www.op.net/~candle maillist@candle.pha.pa.us            |  (610)
853-3000+  If your life is a hard drive,     |  830 Blythe Avenue +  Christ can be your backup.        |  Drexel Hill,
Pennsylvania19026
 

Bruce Momjian wrote:
> 
> > It seems to me there's no fundamental reason why there couldn't be
> > two VACUUMs running concurrently in a database.  With the locking
> > we are doing now, it should be safe enough.  So, I'd like to propose
> > that we get rid of the pg_vlock lock file.  It doesn't have any useful
> > purpose but it does force manual intervention by the dbadmin to recover
> > if a VACUUM crashes :-(
> >
> > Comments?  Did I miss something about why we can't have more than one
> > vacuum process?
> 
> I vote for removal.  Lock files are hacks, usually.

Agreed.

Vadim