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From: Tom Lane <[email protected]>
To: Richard Guo <[email protected]>
Cc: Michael Paquier <[email protected]>
Cc: PostgreSQL-development <[email protected]>
Cc: Alexander Lakhin <[email protected]>
Subject: Re: A failure in prepared_xacts test
Date: Mon, 29 Apr 2024 21:48:13 -0400
Message-ID: <[email protected]> (raw)
In-Reply-To: <CAMbWs48adH1Am=tszAqyq3UtEhDCsFL22U8Jzq0EpPAA6tOd9A@mail.gmail.com>
References: <CAMbWs4-mWCGbbE_bne5=AfqjYGDaUZmjCw2+soLjrdNA0xUDFw@mail.gmail.com>
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	<CAMbWs48uTLZT14aaBaEg7cpB6ercU5wm9+WfGLGC3VoP28gfCA@mail.gmail.com>
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Richard Guo <[email protected]> writes:
> +1.  I'm kind of worried that the expansion of parallelization could
> lead to more instances of instability.  Alexander mentioned one such
> case at [1].  I haven't looked into it though.
> [1] https://www.postgresql.org/message-id/cbf0156f-5aa1-91db-5802-82435dda03e6%40gmail.com

The mechanism there is pretty obvious: a plancache flush happened
at just the wrong (right?) time and caused the output to change,
as indeed the comment acknowledges:

 -- currently, this fails due to cached plan for "r.f1 + 1" expression
 -- (but if debug_discard_caches is on, it will succeed)

I wonder if we shouldn't just remove that test case as being
too unstable -- especially since it's not proving much anyway.

			regards, tom lane






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