Received: from malur.postgresql.org ([217.196.149.56])
	by arkaria.postgresql.org with esmtps (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256)
	(Exim 4.92)
	(envelope-from <pgsql-hackers-owner+archive@lists.postgresql.org>)
	id 1n4LKm-0001AK-VX
	for pgsql-hackers@arkaria.postgresql.org; Mon, 03 Jan 2022 11:17:00 +0000
Received: from localhost ([127.0.0.1] helo=malur.postgresql.org)
	by malur.postgresql.org with esmtp (Exim 4.92)
	(envelope-from <pgsql-hackers-owner+archive@lists.postgresql.org>)
	id 1n4LKl-0003fY-Oc
	for pgsql-hackers@arkaria.postgresql.org; Mon, 03 Jan 2022 11:16:59 +0000
Received: from magus.postgresql.org ([2a02:c0:301:0:ffff::29])
	by malur.postgresql.org with esmtps (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256)
	(Exim 4.92)
	(envelope-from <x4mmm@yandex-team.ru>)
	id 1n4LKl-0003fP-Ff
	for pgsql-hackers@lists.postgresql.org; Mon, 03 Jan 2022 11:16:59 +0000
Received: from forwardcorp1p.mail.yandex.net ([2a02:6b8:0:1472:2741:0:8b6:217])
	by magus.postgresql.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256)
	(Exim 4.92)
	(envelope-from <x4mmm@yandex-team.ru>)
	id 1n4LKj-0001eB-P0
	for pgsql-hackers@lists.postgresql.org; Mon, 03 Jan 2022 11:16:59 +0000
Received: from iva8-c5ee4261001e.qloud-c.yandex.net (iva8-c5ee4261001e.qloud-c.yandex.net [IPv6:2a02:6b8:c0c:a8a6:0:640:c5ee:4261])
	by forwardcorp1p.mail.yandex.net (Yandex) with ESMTP id D3C482E09DD;
	Mon,  3 Jan 2022 14:16:55 +0300 (MSK)
Received: from 2a02:6b8:c0c:1086:0:640:dc79:83bf (2a02:6b8:c0c:1086:0:640:dc79:83bf [2a02:6b8:c0c:1086:0:640:dc79:83bf])
	by iva8-c5ee4261001e.qloud-c.yandex.net (mxbackcorp/Yandex) with HTTP id rGPUnx0MhuQ1-GtMaVUmb;
	Mon, 03 Jan 2022 14:16:55 +0300
X-Yandex-Fwd: 1
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=yandex-team.ru; s=default;
	t=1641208615; bh=my0dKsmUuLcFljW72RIhtxzqAOf8Q34DZI75Z25sIlo=;
	h=References:Date:Message-Id:Cc:Subject:In-Reply-To:To:From;
	b=eFd9U04CIJfaYPmkEUHLhiW8I/Pjcyzxl1ZrktJ4AWnpQ9h6lNAXranMAaawuWdLz
	 R2Wzhgb5mxpBZ3cU81zsumepXeeukYfLsRTvmA1Nk8c7RnzdqTZYRGM9QTvRFxvDWB
	 bIepYMEG8kpA4ZnM+h8C0+7eVWilS6D3rgGBrfrs=
Authentication-Results: iva8-c5ee4261001e.qloud-c.yandex.net; dkim=pass header.i=@yandex-team.ru
Received: by iva8-dc7983bf477b.qloud-c.yandex.net with HTTP;
	Mon, 03 Jan 2022 14:16:55 +0300
From: Andrey Borodin <x4mmm@yandex-team.ru>
To: Justin Pryzby <pryzby@telsasoft.com>
Cc: pgsql-hackers@lists.postgresql.org,
	Daniil Zakhlystov <usernamedt@yandex-team.ru>
In-Reply-To: <20220101172504.GW24477@telsasoft.com>
References: <ABAA09C6-BB95-47A5-890D-90353533F9AC@yandex-team.ru> <20220101172504.GW24477@telsasoft.com>
Subject: Re: libpq compression (part 2)
MIME-Version: 1.0
X-Mailer: Yamail [ http://yandex.ru ] 5.0
Date: Mon, 03 Jan 2022 16:16:55 +0500
Message-Id: <540991641208615@iva8-dc7983bf477b.qloud-c.yandex.net>
Content-Transfer-Encoding: 7bit
Content-Type: text/plain
List-Id: <pgsql-hackers.lists.postgresql.org>
List-Help: <https://lists.postgresql.org/manage/>
List-Subscribe: <https://lists.postgresql.org/manage/>
List-Post: <mailto:pgsql-hackers@lists.postgresql.org>
List-Owner: <mailto:pgsql-hackers-owner@lists.postgresql.org>
List-Archive: <https://www.postgresql.org/list/pgsql-hackers>
Archived-At: <https://www.postgresql.org/message-id/540991641208615%40iva8-dc7983bf477b.qloud-c.yandex.net>
Precedence: bulk


> Maybe you should reset the streams between each compression message (even if
> it's using the same compression algorithm). This might allow better
> compression.

AFAIK on the contrary - longer data sequence usually compresses better. The codec can use knowledge about prior data to better compress current bytes.

Best regards, Andrey Borodin.