Received: from malur.postgresql.org ([217.196.149.56]) by arkaria.postgresql.org with esmtps (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.96) (envelope-from ) id 1wccrx-003Unj-2J for pgsql-general@arkaria.postgresql.org; Thu, 25 Jun 2026 05:43:21 +0000 Received: from localhost ([127.0.0.1] helo=malur.postgresql.org) by malur.postgresql.org with esmtp (Exim 4.96) (envelope-from ) id 1wccrw-003tXn-1q for pgsql-general@arkaria.postgresql.org; Thu, 25 Jun 2026 05:43:20 +0000 Received: from makus.postgresql.org ([2001:4800:3e1:1::229]) by malur.postgresql.org with esmtps (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.96) (envelope-from ) id 1wccrw-003tXf-0S for pgsql-general@lists.postgresql.org; Thu, 25 Jun 2026 05:43:20 +0000 Received: from mail-wr1-x430.google.com ([2a00:1450:4864:20::430]) by makus.postgresql.org with esmtps (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256 (Exim 4.98.2) (envelope-from ) id 1wccrt-000000008QX-2CdD for pgsql-general@lists.postgresql.org; Thu, 25 Jun 2026 05:43:18 +0000 Received: by mail-wr1-x430.google.com with SMTP id ffacd0b85a97d-46def4bd5e8so87445f8f.1 for ; Wed, 24 Jun 2026 22:43:16 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1782366194; cv=none; d=google.com; s=arc-20260327; b=dxmNMNU8QXJOK78bwaXOs/3pTJERsleJ2cPzPBu1VWEw2vxZQD3qHpyB9glcKumg39 9bNRQE7wUr7G8JpGWFdjRmjsORPjBhyKkUrCia/Hdk43suI2qNB53lGfWrs2TO8S+Gqm d9elrxGPlG6MAD/mUwcNLemID98NGrsarT02uDg+9E6TpeaRM+MWAJ/atvTFOtLurj2v yQu2+NTSNjx2x1Bmye1EdJCokYaq6W745w9J2yOKYB7Vls99njMGlR8GJ8eK9nfMF50R z3unrvpHXv++u4ggb6UicHZ+7DKsO/+qdBuWip34ChELmvXPt0E8jb2MOSdWKiFh8rcT iG0w== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20260327; h=content-transfer-encoding:cc:to:subject:message-id:date:from :in-reply-to:references:mime-version:dkim-signature; bh=XGDutLZlIz177/By3YHc09XR5EHHr0V8c7q6NjLM3Z4=; fh=Ql2QINMmYArxn7Sz+BhF2A/MwWMzAnkH0xAE8+2Z1Xs=; b=AE261kVTp/RBUA+gtk9dXb5v4ue1sTech0/r51XJwksqpTejmMRGFx7JRSwF+yoBXF nzTPUevnkG+JzhqChtFbSdD9CKKw2VvXVULZ8ng5cUIvHDPdKnDLLAsgutd7RpzXjSaH RrJ9NEFtr6svt1EFSZpr3zcB8wO0stLypSHFU9Bi+wMQXBX5FiPUJjRY+VFDJ/V89Nsm ESm/UP3XBXIbYTSEiR2PYR+9/xn6EhwT1NJYSN0WSW9/qg1vJnUTdbadZQyu5/1JL1ve 5shduaE+i5lqwpWvknr4WgGrEnvGGzdmRX0/WHDyaOvEa+mszgJ5YvocpXbhZAu0rooo flpw==; darn=lists.postgresql.org ARC-Authentication-Results: i=1; mx.google.com; arc=none DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=bowt-ie.20251104.gappssmtp.com; s=20251104; t=1782366194; x=1782970994; darn=lists.postgresql.org; h=content-transfer-encoding:cc:to:subject:message-id:date:from :in-reply-to:references:mime-version:from:to:cc:subject:date :message-id:reply-to; bh=XGDutLZlIz177/By3YHc09XR5EHHr0V8c7q6NjLM3Z4=; b=xjK86qrfHu56qCAkYUnyIh8X1o49fmy+7yaYvvEC4fDms5N4DBTy1U8fGWHx7JCl2a QgpdVoj/yD/5M33Pr4iFHRJQeI6laMPNtm9ORbJypW2CxyAz5U5V3+pzHSoA+OetD3WQ OLvrpkbeFQDIAXGKAx3s3OEI3boymBqKCLn8f4ggRPSVrPO+f7EphLIiM+SgsjdV3zVg JxNnwGkdrtUuEoAs0XYjXFsj0oGg2rt6tHT1dTugDynbIDcHm/Y42drVwKT5PpFzPDn+ JkLfDhHtdYft/7g3PZ8nM9DBIkMC3yt7xN70COcoQi0O+WRFcZn1BTd+JFHH9ZevuwO/ Fj7A== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1782366194; x=1782970994; h=content-transfer-encoding:cc:to:subject:message-id:date:from :in-reply-to:references:mime-version:x-gm-gg:x-gm-message-state:from :to:cc:subject:date:message-id:reply-to; bh=XGDutLZlIz177/By3YHc09XR5EHHr0V8c7q6NjLM3Z4=; b=D+L4Wr7qYavCXhN5yZePUcgoZIPwBOjHlVCowjcG8duNc43zZoLRPExkc5gYrfXRIF COZgfF76FfwPGEhDU65d57LnFAsGy2hRV8t10A62a/Ko8A+DBT2kUubwMpPK/RuvnJSz h8PlxncJPr0SddRnkyqaONjMATlPj4qW6g9tV8Q2OJmcM2DuJIsc+9FjxO944rPx1CbW Kg45vERsNNOiE1QKtvpr6BgFKFayTKbztRoE69pb/GOnzW0lIvSvC5Tnoc02/BYbt5wq j2WX+D4qca9ocNZ7I/4hSesSl1eG6c1a5yzwirt4uSq43YEIQ9QgdABoO2TPnc8rs6++ FRQA== X-Gm-Message-State: AOJu0YzfgxsewDg8GIjQDbKcljkCzAEHQDE3ezGPxfadj+ZGaOofBDrU C5dIjXAPMfB9eOMKGQ05usDlexrUfmKyPQZ5BnAAWJpFZ5nsevTvTfIXzItBNXKbBbhQiH5Ld/1 S3eLOt72haiNGk0wQgAXmQYjsPX3qoMnBHgLMWeqJgQ== X-Gm-Gg: AfdE7clG5y+V1Uf87VxelZRHzXEClJmjF8r1kFmD04JHxkWi5CMPogx4aplHsp2+Ito f2otbc7XPm2Q5f7QAvBg5wFagxwsHbNo20glGhWwVog6ZIT0Xbd9YpGUBtPEm9fQA/mBqeSQ2Ce 6Pui3urAJlBtyimQzug3hzo5Hn5PcM1GQgnlx8jedv7l+gP6cSMH1/INW2k/4LMyHyvbDKrnMSM kTMeo2tCpdpvuamhgu+0efZl27neawUe1CRdoCB5V51zSLo4rNcIg40PG4Twdq3W+eBW9lD73Jn lEeV7jt6JZlhEJrIWdrpv8CTUnPhWQJ3/qE4iWRHl+g= X-Received: by 2002:a05:6000:4b1d:b0:46d:2ee6:ec74 with SMTP id ffacd0b85a97d-46dc1c9434fmr1093943f8f.38.1782366194185; Wed, 24 Jun 2026 22:43:14 -0700 (PDT) MIME-Version: 1.0 References: In-Reply-To: From: Peter Geoghegan Date: Thu, 25 Jun 2026 01:42:47 -0400 X-Gm-Features: AVVi8CeJLzSF_0wmVyK3EYPAUnuHwZ8UIcPq08IZRBYLK0k6y6kfZ0_PivR7X7c Message-ID: Subject: Re: Pre-PG18 parallel scan estimation: accessing planned worker count from amestimateparallelscan() To: Sivaprasad Cc: pgsql-general@lists.postgresql.org Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable List-Id: List-Help: List-Subscribe: List-Post: List-Owner: List-Archive: Archived-At: Precedence: bulk On Wed, Jun 24, 2026 at 9:46=E2=80=AFPM Sivaprasad wrote: > My question: prior to PG18, was there any supported mechanism by which an= index AM could determine the planner's intended parallel worker count duri= ng scan estimation? No. --=20 Peter Geoghegan