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 4.94.2) (envelope-from ) id 1sRopL-001LGR-FW for pgsql-general@arkaria.postgresql.org; Thu, 11 Jul 2024 08:06:55 +0000 Received: from localhost ([127.0.0.1] helo=malur.postgresql.org) by malur.postgresql.org with esmtp (Exim 4.94.2) (envelope-from ) id 1sRopJ-00C7hE-RS for pgsql-general@arkaria.postgresql.org; Thu, 11 Jul 2024 08:06:53 +0000 Received: from magus.postgresql.org ([2a02:c0:301:0:ffff::29]) by malur.postgresql.org with esmtps (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.94.2) (envelope-from ) id 1sRopJ-00C7h5-Bp for pgsql-general@lists.postgresql.org; Thu, 11 Jul 2024 08:06:53 +0000 Received: from mail-ed1-x531.google.com ([2a00:1450:4864:20::531]) by magus.postgresql.org with esmtps (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256 (Exim 4.94.2) (envelope-from ) id 1sRopG-001WYJ-QO for pgsql-general@lists.postgresql.org; Thu, 11 Jul 2024 08:06:52 +0000 Received: by mail-ed1-x531.google.com with SMTP id 4fb4d7f45d1cf-58b447c5112so778955a12.3 for ; Thu, 11 Jul 2024 01:06:50 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=cybertec-at.20230601.gappssmtp.com; s=20230601; t=1720685209; x=1721290009; darn=lists.postgresql.org; h=mime-version:user-agent:content-transfer-encoding:autocrypt :references:in-reply-to:date:cc:to:from:subject:message-id:from:to :cc:subject:date:message-id:reply-to; bh=5CNwRJTX7TR/lgwvNnWUrnh47PuzbRVRT83WW9ozcpQ=; b=N3eqtfCTYhMCdXu9QIC8QMJJGjstoIf4ZO4ufBT8blPqySbrvcY2QXK3ACmV9w5PXc H/sPHLJ+a8/mjrdgRibofg3tdM/qXISm5rAgNJRYPFKx97LJwkuHcr7neM8aILPJ8stR 7MCd8xmMJjkrw2YgnlTECot9AAWD02lL5kv1NAm2UxXL0f/y2KnIltjyCCppf7zlSiU6 s4c1YHEiIGQRsR2kTssi+E3l7d4T6y+ixJheKD+QutUici4vrv2sZhJLim8uJfmQ6ls5 3BQBOdtT/QdcqijM66nl0irLbFvvl0lMlxWRGcEPlikzOnThS71MV18O4ZyhmwWdnXC9 a5xQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1720685209; x=1721290009; h=mime-version:user-agent:content-transfer-encoding:autocrypt :references:in-reply-to:date:cc:to:from:subject:message-id :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=5CNwRJTX7TR/lgwvNnWUrnh47PuzbRVRT83WW9ozcpQ=; b=w11GRGgpvdV+vhjShArq/y7EcjM1KJAwIyGCbs5WgoDiRvQ7EOLEUeL6/UDez+DpNj VYLZCmO576s4Q+lr3K+dKJmYDULcL/rqpbwxM180GSPa+ma6MY7SwklyGvcQUCr8PZRC WmN40nU5uuK08F2Sjmn7ftF02yraxmzaOHJmCreXc5S5jkIBiXH164HvBe6SMwrmR53S iiMZgttaz3pxYMxK7EWmon5Hv5o8IPp7ADvgT8sBrGlmuWnXStQmz7wZV3T3w812OcJx SoJF2FVG9kUH+0WCFLpPUy6imXONwB+W7JAx7u3gqr0Yt803VbrZpT7yhMQ4mj1hJ+im 9l2Q== X-Gm-Message-State: AOJu0Ywg5O9i62WKtNq0WNhizoEvFncdPRCzFXiOo3Ep9jA0OMjySvsJ f0R/uSEqNPPz1bYJDJB/RCQ6m6G3Y7NxOJtrGNL+YjMg0ZTYMPauLOgkd1KCs/E= X-Google-Smtp-Source: AGHT+IHLqJRRj9sBQ37xr3SrOi0fvxwtLaFjbNutW3+/+QjbAipeupAnnO2KoRfPr9vOt2nK5z2MUw== X-Received: by 2002:a50:fa8c:0:b0:57c:70b0:d541 with SMTP id 4fb4d7f45d1cf-594bb674a9amr4848251a12.20.1720685208629; Thu, 11 Jul 2024 01:06:48 -0700 (PDT) Received: from localhost.localdomain ([2001:871:5e:b437:5380:149a:1b63:4c77]) by smtp.gmail.com with ESMTPSA id 4fb4d7f45d1cf-594bba54abdsm3217866a12.9.2024.07.11.01.06.47 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 11 Jul 2024 01:06:48 -0700 (PDT) Message-ID: Subject: Re: Dropping column from big table From: Laurenz Albe To: sud , Ron Johnson Cc: pgsql-general Date: Thu, 11 Jul 2024 10:06:47 +0200 In-Reply-To: References: Autocrypt: addr=laurenz.albe@cybertec.at; prefer-encrypt=mutual; keydata=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 bT5UrLvJ2jb99bA9QARzhFaxzyn0F/BUKzuIjRGNs/n6d5dNUFA0kOt8sX+TacmC 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 lDrT4wxdLJ/XCdbPPAyl+lZtOLsaHEEZvYNyTXwZc35dVf3R4/oz20HoG6s7ct8e1 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 36UMAx4ulWMyqJajLNGY0DdG8qIsR5nxRhrnK/mrCidZ8F9/D3bWAl4rjtHlsztN59 +AnW5l0HsQcY9ntFL/zEBOaonjdJf Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable User-Agent: Evolution 3.50.4 (3.50.4-1.fc39) MIME-Version: 1.0 List-Id: List-Help: List-Subscribe: List-Post: List-Owner: List-Archive: Archived-At: Precedence: bulk On Thu, 2024-07-11 at 13:10 +0530, sud wrote: > Dropping will take it's own time for post vacuum however as you > rightly said, it won't be blocking which should be fine.=C2=A0 I am not certain if you understood this correctly. Dropping a column is fast, but doesn't reclaim the space. VACUUM won't block anything, but won't reclaim the space. VACUUM (FULL) will block everything, but will also not reclaim the space. You'd need to use a form of ALTER TABLE that rewrites the table, as indicated in the documentation. However, such an operation will block all access to the table for a long time, and it will temporarily need much more space, because it has to hold both the old and the new copy of the table. Yours, Laurenz Albe