Received: from malur.postgresql.org ([217.196.149.56]) by arkaria.postgresql.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_CBC_SHA1:256) (Exim 4.89) (envelope-from ) id 1inpBo-0005Rr-PH for pgsql-hackers@arkaria.postgresql.org; Sat, 04 Jan 2020 19:34:24 +0000 Received: from localhost ([127.0.0.1] helo=malur.postgresql.org) by malur.postgresql.org with esmtp (Exim 4.89) (envelope-from ) id 1inpBn-0003EG-Jd for pgsql-hackers@arkaria.postgresql.org; Sat, 04 Jan 2020 19:34:23 +0000 Received: from makus.postgresql.org ([2001:4800:3e1:1::229]) by malur.postgresql.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_CBC_SHA1:256) (Exim 4.89) (envelope-from ) id 1inpBn-0003E9-1S for pgsql-hackers@lists.postgresql.org; Sat, 04 Jan 2020 19:34:23 +0000 Received: from mail-yb1-xb35.google.com ([2607:f8b0:4864:20::b35]) by makus.postgresql.org with esmtps (TLS1.3:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.92) (envelope-from ) id 1inpBk-0002uJ-LS for pgsql-hackers@lists.postgresql.org; Sat, 04 Jan 2020 19:34:21 +0000 Received: by mail-yb1-xb35.google.com with SMTP id y67so10555270yba.12 for ; Sat, 04 Jan 2020 11:34:20 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=telsasoft-com.20150623.gappssmtp.com; s=20150623; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to:user-agent; bh=52Wlyn9gGv2B5iDCJedUJgF2v55sednGmVTX0Gs1nrA=; b=A+ZdxOKL5mpDhe8gSly35/jMToVutwWI/8rZj/3lKeUHSqWWG+I1TU65BX2cJ8Kst2 AKN0IBZ7k2tD7cKFAgCzGZfJRkSQzAORtFEG1J+eXEz7k/DEpYK7FfTC0357l3Gfpcbz 47eL/hAGV7fSiE4c8OTvxDOfwYmhQ96/0hGE/asNZfH2jsTnh2NQxD5Ublom90rpOnRs fwJsDkh/gX7iqCqUvd+kZ7XuuhfIzJwHY1roP7gDNjMDK0ywsR8LHSdS4wcSjz1xmeHa CAU/L7xkskM/QOh1mzsgFYMy2nZBBOhgLGfQFjA8P9l+opZj1k18X9KEg0WkL/gPMnvS Qa3A== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to:user-agent; bh=52Wlyn9gGv2B5iDCJedUJgF2v55sednGmVTX0Gs1nrA=; b=cd+5gfQCQoZ+v23cpdkrx4giSAnremzGcxRGwlar9ErAhVpYW+EtMN6DxrX0y2XKyq 4fBgwBJAJQhN1VeZmUmAw+OlgCqXNwD7k0dqNstERrcfBS9KsCjicLrGPzQE/616MaNK lDeP1GniW68zupwgl/86qEhApMCUPw0OPbS7RzR2z5Kh6IfgLle8beJhINBp2yfoRRUQ Wgd8O1VGGPRXV0zo8rtog/zTlcn5SP3yuRZon8PGXZSIjaXdDlww0SGJyzaqC8ghXSXX 6ONqeYHk7/SFwCWjvxStggcA/+cFN2t49CiCDuPwkZtu+Sf1xtYPAh1tAuhUfSvcEV/3 Ohsw== X-Gm-Message-State: APjAAAUc1Mag5A4k95syTbLlA6QBgu1kSYqBUDdW3WIFkKTekfcyVUOQ ZSe83UusOrmSCkc6YCeij9cu5g== X-Google-Smtp-Source: APXvYqy4H42bq5TRS7mwXLnynHYfm3zsYPcZV8RwEEtZ++12NZC0kNKUOGQlzU0dgns9tKsYiAZB3w== X-Received: by 2002:a25:297:: with SMTP id 145mr67174644ybc.321.1578166460016; Sat, 04 Jan 2020 11:34:20 -0800 (PST) Received: from pryzbyj (charmander.telsasoft.com. [50.244.222.1]) by smtp.gmail.com with ESMTPSA id d9sm25906651ywh.55.2020.01.04.11.34.18 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Sat, 04 Jan 2020 11:34:18 -0800 (PST) Received: by pryzbyj (Postfix, from userid 1000) id EF429800964; Sat, 4 Jan 2020 13:34:16 -0600 (CST) Date: Sat, 4 Jan 2020 13:34:16 -0600 From: Justin Pryzby To: pgsql-hackers@lists.postgresql.org Cc: Jeff Janes Subject: Re: allow disabling indexscans without disabling bitmapscans Message-ID: <20200104193416.GX12066@telsasoft.com> References: <20200103141427.GK12066@telsasoft.com> <20200104165047.GW12066@telsasoft.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200104165047.GW12066@telsasoft.com> User-Agent: Mutt/1.5.24 (2015-08-30) List-Id: List-Help: List-Subscribe: List-Post: List-Owner: List-Archive: Precedence: bulk On Sat, Jan 04, 2020 at 10:50:47AM -0600, Justin Pryzby wrote: > > Doesn't enable_indexscan=off accomplish this already? It is possible but > > not terribly likely to switch from index to seq, rather than from index to > > bitmap. (Unless the index scan was being used to obtain an ordered result, > > but a hypothetical enable_bitmapscan=FORCE can't fix that). > > No, enable_indexscan=off implicitly disables bitmap index scans, since it does: I don't know how I went wrong, but the regress tests clued me in..it's as Jeff said. Sorry for the noise. Justin