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From: Tom Lane <[email protected]>
To: Ron Johnson <[email protected]>
Cc: pgsql-generallists.postgresql.org <[email protected]>
Subject: Re: Repeatable Read Isolation Level "transaction start time"
Date: Wed, 25 Sep 2024 13:53:37 -0400
Message-ID: <[email protected]> (raw)
In-Reply-To: <CANzqJaBjwtzLg_bZHkokUJbtA8gy6RpHjirfdBH9OJGfn5=tmw@mail.gmail.com>
References: <[email protected]>
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Ron Johnson <[email protected]> writes:
> But why does "SELECT 1;" need a snapshot?  Heck, why does "SELECT
> <immutable>;" need a snapshot?

Because we're not going to analyze the statement in the amount of
depth needed to make that distinction before we crank up the
transactional machinery.  If it says SELECT, it gets a snapshot.

			regards, tom lane

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