Re: [HACKERS] WIP: Detecting SSI conflicts before reporting constraint violations

2016-04-08 Thread Robert Haas
On Thu, Apr 7, 2016 at 12:20 PM, Kevin Grittner wrote: > On Thu, Apr 7, 2016 at 8:49 AM, Thomas Munro > wrote: > >> Here is a version that includes an attempt to describe the >> situation in the documentation. > > Pushed with minor adjustments to

Re: [HACKERS] WIP: Detecting SSI conflicts before reporting constraint violations

2016-04-07 Thread Kevin Grittner
On Thu, Apr 7, 2016 at 8:49 AM, Thomas Munro wrote: > Here is a version that includes an attempt to describe the > situation in the documentation. Pushed with minor adjustments to the docs. Mostly I thought your new text was more appropriate as just another

Re: [HACKERS] WIP: Detecting SSI conflicts before reporting constraint violations

2016-04-07 Thread Thomas Munro
On Thu, Apr 7, 2016 at 10:42 PM, Kevin Grittner wrote: > On Thu, Apr 7, 2016 at 3:26 AM, Simon Riggs wrote: > >> We agree its a bug, so the deadline doesn't need to constrain us. > > I'm not sure there is consensus across the community on that. > >> I

Re: [HACKERS] WIP: Detecting SSI conflicts before reporting constraint violations

2016-04-07 Thread Kevin Grittner
On Thu, Apr 7, 2016 at 3:26 AM, Simon Riggs wrote: > We agree its a bug, so the deadline doesn't need to constrain us. I'm not sure there is consensus across the community on that. > I suggest we should apply what we have then fix the rest later > when we work out how.

Re: [HACKERS] WIP: Detecting SSI conflicts before reporting constraint violations

2016-04-07 Thread Simon Riggs
On 7 April 2016 at 08:55, Michael Paquier wrote: > On Sun, Mar 27, 2016 at 8:15 AM, Thomas Munro > wrote: > > Realistically I'm not going to have a solution to the third problem > > before the 31st. > > Ping. > We agree its a bug, so

Re: [HACKERS] WIP: Detecting SSI conflicts before reporting constraint violations

2016-04-07 Thread Michael Paquier
On Sun, Mar 27, 2016 at 8:15 AM, Thomas Munro wrote: > Realistically I'm not going to have a solution to the third problem > before the 31st. Ping. -- Michael -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your

Re: [HACKERS] WIP: Detecting SSI conflicts before reporting constraint violations

2016-03-26 Thread Thomas Munro
On Sat, Mar 26, 2016 at 5:04 AM, David Steele wrote: > Hi Thomas, > > On 3/13/16 8:20 PM, Thomas Munro wrote: > >> <...> I will have another look at this in >> a few days but for now I need to do some other things, so I'm posting >> these observations in case they are in

Re: [HACKERS] WIP: Detecting SSI conflicts before reporting constraint violations

2016-03-13 Thread Thomas Munro
On Sat, Mar 12, 2016 at 1:25 AM, Kevin Grittner wrote: > On Thu, Mar 10, 2016 at 11:31 PM, Thomas Munro > wrote: > >> Here's a much simpler version with more comments > >> It handles the same set of isolation test specs. > > I'm impressed that

Re: [HACKERS] WIP: Detecting SSI conflicts before reporting constraint violations

2016-03-11 Thread Kevin Grittner
On Thu, Mar 10, 2016 at 11:31 PM, Thomas Munro wrote: > Here's a much simpler version with more comments > It handles the same set of isolation test specs. I'm impressed that you found a one-line patch that seems to get us 90% of the way to a new guarantee; but I

Re: [HACKERS] WIP: Detecting SSI conflicts before reporting constraint violations

2016-03-11 Thread Kevin Grittner
On Thu, Mar 10, 2016 at 1:50 PM, Simon Riggs wrote: > On 3 February 2016 at 23:12, Thomas Munro > wrote: > >> It quacks suspiciously like a bug. > > Agreed > > What's more important is that is very publicly a bug in the eyes > of others and

Re: [HACKERS] WIP: Detecting SSI conflicts before reporting constraint violations

2016-03-11 Thread Thomas Munro
On Fri, Mar 11, 2016 at 6:31 PM, Thomas Munro wrote: > This patch introduces a drop-in replacement > check_unique_tuple_still_live to call instead of heap_hot_search. The > replacement function also calls heap_hot_search_buffer, but while it > has the buffer it

Re: [HACKERS] WIP: Detecting SSI conflicts before reporting constraint violations

2016-03-10 Thread Thomas Munro
On Fri, Mar 11, 2016 at 6:31 PM, Thomas Munro wrote: > I'm not sure what to make of the pre-existing comment about following > HOT-chains and concurrent index builds (which I moved). Does it mean > there is some way that CREATE INDEX CONCURRENTLY could cause us to

Re: [HACKERS] WIP: Detecting SSI conflicts before reporting constraint violations

2016-03-10 Thread Thomas Munro
On Fri, Mar 11, 2016 at 10:00 AM, Simon Riggs wrote: > On 10 March 2016 at 20:36, Thomas Munro > wrote: >> >> On Fri, Mar 11, 2016 at 8:50 AM, Simon Riggs >> wrote: >> > On 3 February 2016 at 23:12, Thomas Munro >> >

Re: [HACKERS] WIP: Detecting SSI conflicts before reporting constraint violations

2016-03-10 Thread Simon Riggs
On 10 March 2016 at 20:36, Thomas Munro wrote: > On Fri, Mar 11, 2016 at 8:50 AM, Simon Riggs > wrote: > > On 3 February 2016 at 23:12, Thomas Munro > > > wrote: > > > >> > >> It quacks suspiciously like a

Re: [HACKERS] WIP: Detecting SSI conflicts before reporting constraint violations

2016-03-10 Thread Thomas Munro
On Fri, Mar 11, 2016 at 8:50 AM, Simon Riggs wrote: > On 3 February 2016 at 23:12, Thomas Munro > wrote: > >> >> It quacks suspiciously like a bug. > > > Agreed > > What's more important is that is very publicly a bug in the eyes of others >

Re: [HACKERS] WIP: Detecting SSI conflicts before reporting constraint violations

2016-03-10 Thread Simon Riggs
On 3 February 2016 at 23:12, Thomas Munro wrote: > It quacks suspiciously like a bug. > Agreed What's more important is that is very publicly a bug in the eyes of others and should be fixed and backpatched soon. We have a maintenance release coming in a couple

Re: [HACKERS] WIP: Detecting SSI conflicts before reporting constraint violations

2016-02-15 Thread Kevin Grittner
On Wed, Feb 3, 2016 at 5:12 PM, Thomas Munro wrote: > I don't see it as a difficult choice between two reasonable > alternatives. It quacks suspiciously like a bug. That seems a little strong to me; I think it would be an unacceptable change in behavior to

Re: [HACKERS] WIP: Detecting SSI conflicts before reporting constraint violations

2016-02-04 Thread Peter Geoghegan
On Wed, Feb 3, 2016 at 10:48 AM, Robert Haas wrote: > I don't feel qualified to have an opinion on whether this is an > improvement. I'm a little skeptical of changes like this on general > principle because sometimes one clientele wants error A to be reported > rather

Re: [HACKERS] WIP: Detecting SSI conflicts before reporting constraint violations

2016-02-03 Thread Thomas Munro
On Thu, Feb 4, 2016 at 7:48 AM, Robert Haas wrote: > On Sun, Jan 31, 2016 at 5:19 PM, Thomas Munro > wrote: >> As described in a recent Reddit discussion[1] and bug report 9301[2], >> there are scenarios where overlapping concurrent

Re: [HACKERS] WIP: Detecting SSI conflicts before reporting constraint violations

2016-02-03 Thread Robert Haas
On Sun, Jan 31, 2016 at 5:19 PM, Thomas Munro wrote: > As described in a recent Reddit discussion[1] and bug report 9301[2], > there are scenarios where overlapping concurrent read-write sequences > produce serialization failures without constraints, but produce >