Re: [HACKERS] Freezing without cleanup lock

2015-10-26 Thread Masahiko Sawada
On Mon, Oct 26, 2015 at 4:39 AM, Jim Nasby wrote: > On 10/22/15 6:39 PM, Alvaro Herrera wrote: >> >> Jim Nasby wrote: >> >>> That would be the minimal-impact version, yes. But I suspect if we went >>> through the trouble to do that, it would be just as easy to attempt

Re: [HACKERS] Freezing without cleanup lock

2015-10-25 Thread Jim Nasby
On 10/22/15 6:39 PM, Alvaro Herrera wrote: Jim Nasby wrote: That would be the minimal-impact version, yes. But I suspect if we went through the trouble to do that, it would be just as easy to attempt the freeze regardless of what scan_all is set to. You mean if !scan_all we conditional-get

Re: [HACKERS] Freezing without cleanup lock

2015-10-22 Thread Jim Nasby
On 10/21/15 3:14 PM, Alvaro Herrera wrote: Jim Nasby wrote: While warning a client that just did a Slony-based version upgrade to make sure to freeze the new database, it occurred to me that it should be safe to freeze without the cleanup lock. This is interesting because it would allow a

Re: [HACKERS] Freezing without cleanup lock

2015-10-22 Thread Alvaro Herrera
Jim Nasby wrote: > That would be the minimal-impact version, yes. But I suspect if we went > through the trouble to do that, it would be just as easy to attempt the > freeze regardless of what scan_all is set to. You mean if !scan_all we conditional-get the cleanup lock, if we get it then prune,

[HACKERS] Freezing without cleanup lock

2015-10-21 Thread Jim Nasby
While warning a client that just did a Slony-based version upgrade to make sure to freeze the new database, it occurred to me that it should be safe to freeze without the cleanup lock. This is interesting because it would allow a scan_all vacuum to do it's job without blocking on the cleanup

Re: [HACKERS] Freezing without cleanup lock

2015-10-21 Thread Tom Lane
Jim Nasby writes: > While warning a client that just did a Slony-based version upgrade to > make sure to freeze the new database, it occurred to me that it should > be safe to freeze without the cleanup lock. What's your argument for that being safe?

Re: [HACKERS] Freezing without cleanup lock

2015-10-21 Thread Andres Freund
On October 21, 2015 9:47:45 PM GMT+02:00, Tom Lane wrote: >Jim Nasby writes: >> While warning a client that just did a Slony-based version upgrade to > >> make sure to freeze the new database, it occurred to me that it >should >> be safe to freeze

Re: [HACKERS] Freezing without cleanup lock

2015-10-21 Thread Alvaro Herrera
Jim Nasby wrote: > While warning a client that just did a Slony-based version upgrade to make > sure to freeze the new database, it occurred to me that it should be safe to > freeze without the cleanup lock. This is interesting because it would allow > a scan_all vacuum to do it's job without