From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on dcvr.yhbt.net X-Spam-Level: X-Spam-ASN: AS31976 209.132.180.0/23 X-Spam-Status: No, score=-3.0 required=3.0 tests=AWL,BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,RCVD_IN_DNSWL_HI, RCVD_IN_SORBS_SPAM,RP_MATCHES_RCVD shortcircuit=no autolearn=no autolearn_force=no version=3.4.0 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by dcvr.yhbt.net (Postfix) with ESMTP id 5FB2420899 for ; Wed, 9 Aug 2017 00:02:18 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752492AbdHIACN (ORCPT ); Tue, 8 Aug 2017 20:02:13 -0400 Received: from mail-ua0-f177.google.com ([209.85.217.177]:36143 "EHLO mail-ua0-f177.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751970AbdHIACL (ORCPT ); Tue, 8 Aug 2017 20:02:11 -0400 Received: by mail-ua0-f177.google.com with SMTP id k43so22278625uaf.3 for ; Tue, 08 Aug 2017 17:02:10 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=spearce.org; s=google; h=mime-version:in-reply-to:references:from:date:message-id:subject:to :cc; bh=RaXaRBywd4oDQe/MEnI6uNl+2A3/C4pn+xzb24aM29Q=; b=TN7yY5wi/mnwzSbThqvX9RlX5rd+ILu1hBrt2AIx7WgP2RCAjrA7wpin7I7wFJPZ/x gzfNywI8sQwHLfShEIm65vtGW8n4bCu9NJ/zYoLb7L9jNeCEEIlJ2/x5EpbPdFZ9+iCl 96PNH0OYNoeisl2vsVgNgf65KGXM3dkqtCbiY= 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=RaXaRBywd4oDQe/MEnI6uNl+2A3/C4pn+xzb24aM29Q=; b=FPBMvnA0nLgenDHi8f7XPe2hEtFzPRUMkg6YTGmAjMarFXvL9LVIwTvH5jcs//C3MF bdquxPiUWllAG3cGX2fnxezIs5TWzRfTSpddNSqc9LH3uNu1JjsCy1XTINhCX1n4PzEu wRPW/pNG4Lq72DdW9NfDtNcELsV/a0/VDcES3b1SHY3bKfd4jVbGGaBAPdDbJZhJjAw2 vyFURz4det7j+RXjU2/82gEUixxaoYOxO4E7HdpCj/x1XZV52mUFNOSBLbfZG59PNVW6 yhe0loIYKoqObk1uMsfKyzFUSGwBqbJieRYAF+DnBlQmJtlr3zdP7a74vCzRlqVcWQeH 4NKA== X-Gm-Message-State: AHYfb5jydAqhdeMxoYNQG/Ah7WE96QehcxYIKtoVplltUx1eYtoS2041 gdHJiJZI4NcGBa0I9OtnomWwVMc7wedr X-Received: by 10.176.75.167 with SMTP id v39mr4482128uaf.11.1502236930280; Tue, 08 Aug 2017 17:02:10 -0700 (PDT) MIME-Version: 1.0 Received: by 10.103.83.7 with HTTP; Tue, 8 Aug 2017 17:01:49 -0700 (PDT) In-Reply-To: References: From: Shawn Pearce Date: Tue, 8 Aug 2017 17:01:49 -0700 Message-ID: Subject: Re: reftable [v6]: new ref storage format To: Junio C Hamano Cc: git , Jeff King , Michael Haggerty , David Borowitz , Stefan Beller Content-Type: text/plain; charset="UTF-8" Sender: git-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: git@vger.kernel.org On Tue, Aug 8, 2017 at 4:34 PM, Junio C Hamano wrote: > Shawn Pearce writes: > >> Given that the index can now also be multi-level, I don't expect to >> see a 2G index. A 2G index forces the reader to load the entire 2G to >> take advantage of the restart table. It may be more efficient for such >> a reader to have had the writer make a mutli-level index, instead of a >> single monster index block. And so perhaps the writer shouldn't make a >> 2G index block that she is forced to buffer. :) > > Ah, OK, then it is sensible to have all table blocks to have the > same format, and restart at the beginning to help readers would be a > fine choice. For the same "let's make them as consistent" sake, I > am tempted to suggest that we lift "the index block can be 2G" and > have it also be within uint_24(), perhaps? Otherwise the readers > would have to read (or mmap) the whole 2G. Gah. I just finished moving the restart table back to the end of the block. :) However, I think I can agree with the index fitting into the uint24 size of 15M, and asking writers making an index that exceeds that to use multi-level indexing.