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Wed, 12 Sep 2018 06:20:09 -0400 (EDT) Received: from mailfrontend2 ([10.202.2.163]) by compute7.internal (MEProxy); Wed, 12 Sep 2018 06:20:09 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d= messagingengine.com; h=cc:content-transfer-encoding:content-type :date:from:in-reply-to:message-id:mime-version:references :subject:to:x-me-sender:x-me-sender:x-sasl-enc; s=fm3; bh=+ox3X4 w29lGcmzNu+XAZknhVbOKwtbU1dfLUyqCn7A4=; b=JEd9oFE7RJXQF3n+eeb9z5 LfHdDiZeH0w9CvkHCAPMcnWGB3GZ+PG+SEiji8kvrA4k1GzU9a1Mf2VJyKTl5rRZ Ol4KycIGmVPlx8i2h1Oq5V+25702vFUIn8moEJtHhOC5Tz94eu/k5MeycjZJCzdb AAsVe24dTlEnZKiQQm8UTa6uC8FEvTTM9hC4H4Qc3DEhKatWqaaU87KaWvMKla5S a7Noan1pwtG0J1vKwKCLfFuU6QkUps4MIv0qJEH3tRD33bO6uwC3lBOh9v57746N HfErwg1Qix3Zj3srfyswUjA/girCIQiHhoDGiZzsVuzSW+f06DpSrPT8h4Aza0ug == X-ME-Proxy: X-ME-Sender: Received: from april.pezone.net (p5df2a2d9.dip0.t-ipconnect.de [93.242.162.217]) by mail.messagingengine.com (Postfix) with ESMTPA id E532D102D1; Wed, 12 Sep 2018 06:20:07 -0400 (EDT) Subject: Re: pg_dump test instability To: Tom Lane , Stephen Frost References: <5137fe12-d0a2-4971-61b6-eb4e7e8875f8@2ndquadrant.com> <32399.1535379095@sss.pgh.pa.us> <20180827144138.GO3326@tamriel.snowman.net> <1665.1535381158@sss.pgh.pa.us> <20180827155943.GP3326@tamriel.snowman.net> <1765.1535482037@sss.pgh.pa.us> Cc: pgsql-hackers From: Peter Eisentraut Openpgp: preference=signencrypt Autocrypt: addr=peter.eisentraut@2ndquadrant.com; 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Intel Mac OS X 10.13; rv:52.0) Gecko/20100101 Thunderbird/52.9.1 MIME-Version: 1.0 In-Reply-To: <1765.1535482037@sss.pgh.pa.us> Content-Type: text/plain; charset=windows-1252 Content-Language: en-US Content-Transfer-Encoding: 8bit List-Id: List-Help: List-Subscribe: List-Post: List-Owner: List-Archive: Precedence: bulk On 28/08/2018 20:47, Tom Lane wrote: > Here's a proposed patch for this. It removes the hacking of the TOC list > order, solving Peter's original problem, and instead sorts-by-size > in the actual parallel dump or restore control code. I have reviewed this patch. I haven't done any major performance tests or the like, but the improvements are clear in principle. It does solve the issue that I had originally reported, when I apply it on top of my development branch. Some small comments on the code: Maybe add a ready_list_free() to go with ready_list_init(), instead of calling pg_free(ready_list.tes) directly. get_next_work_item() has been changed to remove the work item from the ready_list. Maybe rename to something like pop_next_work_item()? I'm confused by what ready_list_remove() is doing when it's not removing the first item. It looks like it's removing all leading items up to the i'th one. Is that what we want? In some cases, we are skipping over things that we are not interested at all, so this would work, but if we're just skipping over an item because of a lock conflict, then it's not right. -- Peter Eisentraut http://www.2ndQuadrant.com/ PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services