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help / color / mirror / Atom feedFrom: Ron Johnson <[email protected]>
To: pgsql-generallists.postgresql.org <[email protected]>
Subject: Re: Repeatable Read Isolation Level "transaction start time"
Date: Wed, 25 Sep 2024 13:50:33 -0400
Message-ID: <CANzqJaBjwtzLg_bZHkokUJbtA8gy6RpHjirfdBH9OJGfn5=tmw@mail.gmail.com> (raw)
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<CAKAnmmLt2ezcf7-LgJkO_oeqK+Ei+XB6F3pHk2mnyadRq3corQ@mail.gmail.com>
<[email protected]>
On Wed, Sep 25, 2024 at 1:45 PM Adrian Klaver <[email protected]>
wrote:
>
>
> On 9/25/24 10:22 AM, Greg Sabino Mullane wrote:
> > On Tue, Sep 24, 2024 at 10:28 AM Tom Lane <[email protected]
> > <mailto:[email protected]>> wrote:
> >
> > It's even looser than that, really: it's the first statement that
> > requires an MVCC snapshot.
> >
> >
> > Hm....so why does "SELECT 1;" work as a transaction start marker then,
> > as opposed to "SHOW work_mem;", which does not? Do we simply consider
> > anything with a SELECT as needing a snapshot?
>
>
> SELECT some_func();
>
> Where some_func() does something that requires a snapshot.
>
>
But why does "SELECT 1;" need a snapshot? Heck, why does "SELECT
<immutable>;" need a snapshot?
--
Death to <Redacted>, and butter sauce.
Don't boil me, I'm still alive.
<Redacted> crustacean!
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Subject: Re: Repeatable Read Isolation Level "transaction start time"
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