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Message-ID: <afa26355-0170-4dfc-a381-024c052d26bf@vondra.me>
Date: Mon, 4 May 2026 15:51:20 +0200
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User-Agent: Mozilla Thunderbird
Subject: Re: EXPLAIN: showing ReadStream / prefetch stats
To: Andres Freund <andres@anarazel.de>
Cc: Melanie Plageman <melanieplageman@gmail.com>,
 Lukas Fittl <lukas@fittl.com>,
 PostgreSQL Hackers <pgsql-hackers@lists.postgresql.org>
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From: Tomas Vondra <tomas@vondra.me>
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Hi,

While looking for something in the EXPLAIN docs, I realized the docs
added by 681daed93169 are considerably less detailed that for the other
EXPLAIN options. It only said "information on I/O" provided by the scan
node, while the other options go into much more details.

The attached patch improves that a little bit - it lists the counters
added to explain. I'll consider going into a little bit more detail,
e.g. regarding what "capacity" or "waits" means.

I'll add this as an open item for PG19, so that I don't forget about it.

regards

-- 
Tomas Vondra

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