On 2018-09-05 19:11:56 -0400, Tom Lane wrote:
> Andres Freund writes:
> > On 2018-09-05 18:45:52 -0400, Tom Lane wrote:
> >> The snapshot has little to do with the query plan, usually. It's about
> >> what view of the database the executed query will see, and particularly
> >> about what view the
> > Queries stop getting re-optimized after 5 times, unless better plans are to
> > be had. In the absence of schema changes or changing search path why is
> > the snapshot needed?
>
> The snapshot has little to do with the query plan, usually. It's about
> what view of the database the execut
Andres Freund writes:
> On 2018-09-05 18:45:52 -0400, Tom Lane wrote:
>> The snapshot has little to do with the query plan, usually. It's about
>> what view of the database the executed query will see, and particularly
>> about what view the parameter input functions will see, if they look.
> Th
On 2018-09-05 18:45:52 -0400, Tom Lane wrote:
> Daniel Wood writes:
> >>> exec_bind_message()
> >>> PushActiveSnapshot(GetTransactionSnapshot());
> >>>
> >>> If there were no input functions, that needed this, nor reparsing or
> >>> reanalyzing needed, and we knew this up front, it'd be a huge
Daniel Wood writes:
>>> exec_bind_message()
>>> PushActiveSnapshot(GetTransactionSnapshot());
>>>
>>> If there were no input functions, that needed this, nor reparsing or
>>> reanalyzing needed, and we knew this up front, it'd be a huge win.
>> Unfortunately, that's not the case, so I think tr
> > exec_bind_message()
> > PushActiveSnapshot(GetTransactionSnapshot());
>
> > If there were no input functions, that needed this, nor reparsing or
> > reanalyzing needed, and we knew this up front, it'd be a huge win.
>
> Unfortunately, that's not the case, so I think trying to get
Hi,
On 2018-09-05 12:31:04 -0700, Daniel Wood wrote:
> NOTE:
>
> In GetSnapshotData because pgxact, is declared volatile, the compiler will
> not reduce the following two IF tests into a single test:
>
>
> if (pgxact->vacuumFlags & PROC_IN_LOGICAL_DECODING)
> continue;
>
>
>
Daniel Wood writes:
> In particular:
> exec_bind_message()
> PushActiveSnapshot(GetTransactionSnapshot());
> If there were no input functions, that needed this, nor reparsing or
> reanalyzing needed, and we knew this up front, it'd be a huge win.
Unfortunately, that's not the case, s
