Thread: Re: [PATCHES] Implementing RESET CONNECTION ...

Re: [PATCHES] Implementing RESET CONNECTION ...

From
Oliver Jowett
Date:
(cc'ing -hackers)

Karel Zak wrote:

> I think command status is common and nice feedback for client. I think
> it's more simple change something in JDBC than change protocol that is
> shared between more tools.

There is a bit of a queue of changes that would be nice to have but
require a protocol version change. If we're going to change the protocol
for any of those we might as well handle RESET CONNECTION cleanly too.

> We need some common way how detect on client what's happen on server --
> a way that doesn't mean change protocol always when we add some
> feature/command to backend. The command status is possible use for this.

Command status only works if commands are directly executed. If you can
execute the command indirectly, e.g. via a PL, then you'll miss the
notification. Making RESET a top-level-only command isn't unreasonable,
but using command status won't work as a general approach for notifying
clients.

We have a mechanism for GUC changes that uses a separate message
(ParameterStatus). Perhaps that should be generalized to report
different sorts of connection-related changes.

-O

Re: [PATCHES] Implementing RESET CONNECTION ...

From
Bruce Momjian
Date:
What did we decide on RESET CONNECTION.  Do we want an SQL command or
something only the protocol can do?

---------------------------------------------------------------------------

Oliver Jowett wrote:
> (cc'ing -hackers)
>
> Karel Zak wrote:
>
> > I think command status is common and nice feedback for client. I think
> > it's more simple change something in JDBC than change protocol that is
> > shared between more tools.
>
> There is a bit of a queue of changes that would be nice to have but
> require a protocol version change. If we're going to change the protocol
> for any of those we might as well handle RESET CONNECTION cleanly too.
>
> > We need some common way how detect on client what's happen on server --
> > a way that doesn't mean change protocol always when we add some
> > feature/command to backend. The command status is possible use for this.
>
> Command status only works if commands are directly executed. If you can
> execute the command indirectly, e.g. via a PL, then you'll miss the
> notification. Making RESET a top-level-only command isn't unreasonable,
> but using command status won't work as a general approach for notifying
> clients.
>
> We have a mechanism for GUC changes that uses a separate message
> (ParameterStatus). Perhaps that should be generalized to report
> different sorts of connection-related changes.
>
> -O
>
> ---------------------------(end of broadcast)---------------------------
> TIP 7: don't forget to increase your free space map settings
>

--
  Bruce Momjian                        |  http://candle.pha.pa.us
  pgman@candle.pha.pa.us               |  (610) 359-1001
  +  If your life is a hard drive,     |  13 Roberts Road
  +  Christ can be your backup.        |  Newtown Square, Pennsylvania 19073

Re: [PATCHES] Implementing RESET CONNECTION ...

From
Christopher Kings-Lynne
Date:
What would be absolutely ideal is a reset connection command, plus some
way of knowing via the protocol if it's needed or not.

Chris

Bruce Momjian wrote:
> What did we decide on RESET CONNECTION.  Do we want an SQL command or
> something only the protocol can do?
>
> ---------------------------------------------------------------------------
>
> Oliver Jowett wrote:
>
>>(cc'ing -hackers)
>>
>>Karel Zak wrote:
>>
>>
>>>I think command status is common and nice feedback for client. I think
>>>it's more simple change something in JDBC than change protocol that is
>>>shared between more tools.
>>
>>There is a bit of a queue of changes that would be nice to have but
>>require a protocol version change. If we're going to change the protocol
>>for any of those we might as well handle RESET CONNECTION cleanly too.
>>
>>
>>>We need some common way how detect on client what's happen on server --
>>>a way that doesn't mean change protocol always when we add some
>>>feature/command to backend. The command status is possible use for this.
>>
>>Command status only works if commands are directly executed. If you can
>>execute the command indirectly, e.g. via a PL, then you'll miss the
>>notification. Making RESET a top-level-only command isn't unreasonable,
>>but using command status won't work as a general approach for notifying
>>clients.
>>
>>We have a mechanism for GUC changes that uses a separate message
>>(ParameterStatus). Perhaps that should be generalized to report
>>different sorts of connection-related changes.
>>
>>-O
>>
>>---------------------------(end of broadcast)---------------------------
>>TIP 7: don't forget to increase your free space map settings
>>
>
>

Re: [PATCHES] Implementing RESET CONNECTION ...

From
Oliver Jowett
Date:
Christopher Kings-Lynne wrote:
> What would be absolutely ideal is a reset connection command, plus some
> way of knowing via the protocol if it's needed or not.

And a way of notifying the client that a reset has happened.

-O