Return-Path: owner-postman Received: from localhost (localhost [127.0.0.1]) by nobozo.CS.Berkeley.EDU (8.6.4/8.6.3) with SMTP id NAA14566 for postgres-dist; Sun, 21 Nov 1993 13:51:20 -0800 Resent-From: POSTGRES mailing list Resent-Message-Id: <199311212151.NAA14566@nobozo.CS.Berkeley.EDU> X-Authentication-Warning: nobozo.CS.Berkeley.EDU: Host localhost didn't use HELO protocol Sender: owner-postman@postgres.Berkeley.EDU X-Return-Path: owner-postman Received: from laphroaig.aoc.NRAO.EDU (laphroaig.aoc.nrao.edu [146.88.5.19]) by nobozo.CS.Berkeley.EDU (8.6.4/8.6.3) with ESMTP id NAA14557 for ; Sun, 21 Nov 1993 13:51:19 -0800 Received: from localhost by laphroaig.aoc.NRAO.EDU (8.6.beta.11/1.3pmg) id VAA16025; Sun, 21 Nov 1993 21:50:46 GMT Message-Id: <199311212150.VAA16025@laphroaig.aoc.NRAO.EDU> Date: Sun, 21 Nov 1993 21:50:46 GMT From: Chris Flatters To: postgres@postgres.Berkeley.EDU Subject: Re: size of data files X-Sun-Charset: US-ASCII Resent-To: postgres-dist@postgres.Berkeley.EDU Resent-Date: Sun, 21 Nov 93 13:51:20 -0800 Resent-XMts: smtp Kent Archie writes: > Is there a way to determine the amount of space actually used > by Postgres tables. I just stored some data in my tables > and they jumped from 0 bytes to 8192. I assume there is > some minimum allocation regardless of the actual data stored. > But can I find the amount due to my data? > I am trying to compare the earlier file-based version > of my application to the Postgres one. > I expect the database to have higher overhead, but how much? The POSTGRES page size is 8k bytes so the storage required for any class is always rounded up to the next multiple of 8k. You can make a rough guess at the table size by multiplying the size of each tuple by the number of tuples in the class and rounding up to a 8k multiple. This may give underestimate the number of 8k pages by one in a few cases since there is a small amount of bookkeeping information stored with each page. Chris Flatters cflatter@nrao.edu