Date: Tue, 29 Mar 2022 18:10:11 +0900 (JST)
Message-Id: <20220329.181011.1401235917653600685.horikyota.ntt@gmail.com>
To: er@xs4all.nl
Cc: pgsql-hackers@lists.postgresql.org
Subject: Re: TRAP: FailedAssertion("HaveRegisteredOrActiveSnapshot()",
 File: "toast_internals.c", Line: 670, PID: 19403)
From: Kyotaro Horiguchi <horikyota.ntt@gmail.com>
In-Reply-To: <20220329.170621.2101149643828659444.horikyota.ntt@gmail.com>
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	<20220328.183646.1041002117568499041.horikyota.ntt@gmail.com>
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At Tue, 29 Mar 2022 17:06:21 +0900 (JST), Kyotaro Horiguchi <horikyota.ntt@gmail.com> wrote in 
> At Mon, 28 Mar 2022 18:36:46 +0900 (JST), Kyotaro Horiguchi <horikyota.ntt@gmail.com> wrote in 
> Then, I found that portal->holdSnapshot is that.  I came up with the
> attached.  It does the follows:
> 
> 1. Teach PlannedStmtRequiresSnapshot() to return true for FetchStmt.
> 
> 2. Use holdSnapshot in RunFromStore if any.
> 
> 
> The rerpducer is reduced to as small as the following.
> 
> CREATE TABLE t (a text);
> INSERT INTO t VALUES('some random text');
> BEGIN;
> DECLARE c CURSOR FOR SELECT * FROM t;
> FETCH ALL IN c;
> 
> But I haven't come up with a reasonable way to generate the 'some
> random text' yet.

I gave up and took a straightforward way to generate one.

I don't like that it uses a fixed length for the random text, but
anyway it works for now...

regards.

-- 
Kyotaro Horiguchi
NTT Open Source Software Center

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