Received: from malur.postgresql.org ([217.196.149.56]) by arkaria.postgresql.org with esmtp (Exim 4.84_2) (envelope-from ) id 1eF7P5-0004Bz-Vw for pgsql-performance@arkaria.postgresql.org; Wed, 15 Nov 2017 23:47:36 +0000 Received: from localhost ([127.0.0.1] helo=postgresql.org) by malur.postgresql.org with smtp (Exim 4.84_2) (envelope-from ) id 1eF7P5-0008Rp-JK for pgsql-performance@arkaria.postgresql.org; Wed, 15 Nov 2017 23:47:35 +0000 Received: from makus.postgresql.org ([2001:4800:1501:1::229]) by malur.postgresql.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_CBC_SHA384:256) (Exim 4.84_2) (envelope-from ) id 1eF7P4-0008RW-Op for pgsql-performance@postgresql.org; Wed, 15 Nov 2017 23:47:35 +0000 Received: from mail-vk0-x22d.google.com ([2607:f8b0:400c:c05::22d]) by makus.postgresql.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_CBC_SHA1:256) (Exim 4.89) (envelope-from ) id 1eF7P1-0005ZN-Hc for pgsql-performance@postgresql.org; Wed, 15 Nov 2017 23:47:33 +0000 Received: by mail-vk0-x22d.google.com with SMTP id o70so7137144vkc.9 for ; Wed, 15 Nov 2017 15:47:31 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=2ndquadrant-com.20150623.gappssmtp.com; s=20150623; h=mime-version:in-reply-to:references:from:date:message-id:subject:to :cc; bh=2hfKg108JiWNvTQQNBIITdjAt7whV6IS6VFbbf60DNg=; b=pz+HG2/QuvVEbOk0kDgQMLX5b+eZmM45rfffrrAkMotvsmqe/E6VvezfL9FhpmgIS8 ncULtyScu24Zl2yMqOuQqzIYWI4bVK7bhGgsoUkT3q0R49n8aoYIoraOBR2k5cPnFTMS iE77N7TEv3W/ey/l6ctchOTlrNewlHPNcmTD+MS+TrfLKZEUt0BrXsYdI8hewLz2Mt4j bF3S9I+i1zZpK4Je4buUN7DpQwzI0U00n8HZoHLzTV7QYkNgDZv8G5lDGpiq70REYRVf pfoKqYSns50UVR+qu7PbJaIZYDzuMLDWGfBDw24b41GNLVX+tk+JPJ4Q0/RhoCB4LuAf w6UQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:in-reply-to:references:from:date :message-id:subject:to:cc; bh=2hfKg108JiWNvTQQNBIITdjAt7whV6IS6VFbbf60DNg=; b=rGO1QTTa5unJknpc3x6A1Ec08NswqYri66mixp0lP6PMLtXclM7z1VM+sav0Eq7JjT jhThZvvS8E2JqO7QmQAqxk+9myqUliGLLfxKw40oA+aKGFHL8y/hmoDmvCcpciEJTVQi jbFsJIU+2ZG9snHme/u4hNySBz9i61DWcmZ6E4McOcRBzj+v9UnhjYHuvtJ4MH94aPET MsFEKsswqCTJX1GJlvkkNAgaRUZf6op7dDI0B6JscWdj78iYmeq48gNQuXus+W2juQ4n SHyNj2vU4SwB3XpGvWRRSBBWaU7UH9oy423A2Ohr43p5EcAItptTCayDuYBlgx+EMOgx aGEQ== X-Gm-Message-State: AJaThX66tx9Jr0L+VhojdZ7Zi4uVzhO0vxtInF4iiDjhBg9VjygOpNlZ xXT0BVnsd//rd7DuiN6L6O9rtCaIcTPCkQTC7L1wcw== X-Google-Smtp-Source: AGs4zMZztCa4cmTxo/8nOeeoA9MlefamU6T+Y9hnCWuGB8uH0NKJA/yVWPpJU5oGgfk4E4BCyvPL9PBC587dG9G0vO4= X-Received: by 10.31.168.82 with SMTP id r79mr9600665vke.150.1510789649652; Wed, 15 Nov 2017 15:47:29 -0800 (PST) MIME-Version: 1.0 Received: by 10.159.50.104 with HTTP; Wed, 15 Nov 2017 15:47:29 -0800 (PST) In-Reply-To: <20171115201913.GX2167@telsasoft.com> References: <20171115201913.GX2167@telsasoft.com> From: David Rowley Date: Thu, 16 Nov 2017 12:47:29 +1300 Message-ID: Subject: Re: CREATE STATISTICS and join selectivity To: Justin Pryzby Cc: postgres performance list Content-Type: text/plain; charset="UTF-8" List-Archive: List-Help: List-ID: List-Owner: List-Post: List-Subscribe: List-Unsubscribe: X-Mailing-List: pgsql-performance Precedence: bulk Sender: pgsql-performance-owner@postgresql.org On 16 November 2017 at 09:19, Justin Pryzby wrote: > I just noticed that PG10 CREATE STATISTICS (dependencies) doesn't seem to work > for joins on multiple columns; is that right? Unfortunately, for now, they're not used for join selectivity estimates, only for the base rel selectivities. That's all there was time for with PG10. This is highly likely to be improved sometime in the future. -- David Rowley http://www.2ndQuadrant.com/ PostgreSQL Development, 24x7 Support, Training & Services -- Sent via pgsql-performance mailing list (pgsql-performance@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance