Re: [HACKERS] small exclusion constraints patch

2010-07-15 Thread Tom Lane
Jeff Davis pg...@j-davis.com writes: Currently, the check for exclusion constraints performs a sanity check that's slightly too strict -- it assumes that a tuple will conflict with itself. That is not always the case: the operator might be , in which case it's perfectly valid for the search

Re: [HACKERS] small exclusion constraints patch

2010-05-30 Thread Marko Tiikkaja
On 2010-05-30 06:55 +0300, Robert Haas wrote: On Sat, May 29, 2010 at 11:40 PM, Tom Lane t...@sss.pgh.pa.us wrote: Yes, I've seen Jeff's example. It's a cute hack but somehow I doubt that there is going to be a land rush to implement such things. Can you point to any pre-existing example

Re: [HACKERS] small exclusion constraints patch

2010-05-30 Thread Tom Lane
Marko Tiikkaja marko.tiikk...@cs.helsinki.fi writes: On 2010-05-30 06:55 +0300, Robert Haas wrote: I've often wished for the ability to constrain a tale to hold just one row, so I don't find that use case implausible at all. As I pointed out in

Re: [HACKERS] small exclusion constraints patch

2010-05-30 Thread Robert Haas
On Sun, May 30, 2010 at 10:01 AM, Tom Lane t...@sss.pgh.pa.us wrote: Marko Tiikkaja marko.tiikk...@cs.helsinki.fi writes: On 2010-05-30 06:55 +0300, Robert Haas wrote: I've often wished for the ability to constrain a tale to hold just one row, so I don't find that use case implausible at all.

Re: [HACKERS] small exclusion constraints patch

2010-05-30 Thread Tom Lane
Robert Haas robertmh...@gmail.com writes: ... The fact that not very many people will want to do something is not a reason to prevent it. It's not about preventing it for no reason. The proposed patch removes a significant sanity check from code that still hasn't gotten out of beta. I might be

Re: [HACKERS] small exclusion constraints patch

2010-05-29 Thread Robert Haas
On Fri, May 28, 2010 at 10:32 PM, Bruce Momjian br...@momjian.us wrote: Tom Lane wrote: Jeff Davis pg...@j-davis.com writes: Currently, the check for exclusion constraints performs a sanity check that's slightly too strict -- it assumes that a tuple will conflict with itself. That is not

Re: [HACKERS] small exclusion constraints patch

2010-05-29 Thread Tom Lane
Robert Haas robertmh...@gmail.com writes: The only disadvantage I see of just documenting this is that someone might write a user-defined index opclass that works like this, and they won't be able to use this until at least 9.1 (or at least, not without patching the source). I don't actually

Re: [HACKERS] small exclusion constraints patch

2010-05-29 Thread David Fetter
On Sat, May 29, 2010 at 06:11:57PM -0400, Tom Lane wrote: Robert Haas robertmh...@gmail.com writes: The only disadvantage I see of just documenting this is that someone might write a user-defined index opclass that works like this, and they won't be able to use this until at least 9.1 (or

Re: [HACKERS] small exclusion constraints patch

2010-05-29 Thread Robert Haas
On Sat, May 29, 2010 at 6:11 PM, Tom Lane t...@sss.pgh.pa.us wrote: Robert Haas robertmh...@gmail.com writes: The only disadvantage I see of just documenting this is that someone might write a user-defined index opclass that works like this, and they won't be able to use this until at least

Re: [HACKERS] small exclusion constraints patch

2010-05-29 Thread Tom Lane
Robert Haas robertmh...@gmail.com writes: On Sat, May 29, 2010 at 6:11 PM, Tom Lane t...@sss.pgh.pa.us wrote: Or, to put it differently: if nobody's done that in the past twenty years, why is it likely to happen before 9.1? Hmm. Well suppose we bet a dollar on whether that will happen or

Re: [HACKERS] small exclusion constraints patch

2010-05-29 Thread Robert Haas
On Sat, May 29, 2010 at 11:40 PM, Tom Lane t...@sss.pgh.pa.us wrote: Robert Haas robertmh...@gmail.com writes: On Sat, May 29, 2010 at 6:11 PM, Tom Lane t...@sss.pgh.pa.us wrote: Or, to put it differently: if nobody's done that in the past twenty years, why is it likely to happen before 9.1?

Re: [HACKERS] small exclusion constraints patch

2010-05-28 Thread Bruce Momjian
Tom Lane wrote: Jeff Davis pg...@j-davis.com writes: Currently, the check for exclusion constraints performs a sanity check that's slightly too strict -- it assumes that a tuple will conflict with itself. That is not always the case: the operator might be , in which case it's perfectly

[HACKERS] small exclusion constraints patch

2010-05-21 Thread Jeff Davis
Currently, the check for exclusion constraints performs a sanity check that's slightly too strict -- it assumes that a tuple will conflict with itself. That is not always the case: the operator might be , in which case it's perfectly valid for the search for conflicts to not find itself. This

Re: [HACKERS] small exclusion constraints patch

2010-05-21 Thread Tom Lane
Jeff Davis pg...@j-davis.com writes: Currently, the check for exclusion constraints performs a sanity check that's slightly too strict -- it assumes that a tuple will conflict with itself. That is not always the case: the operator might be , in which case it's perfectly valid for the search