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Re: [Monotone-devel] responses to some IRC discussion of 'automate'
From: |
Thomas Moschny |
Subject: |
Re: [Monotone-devel] responses to some IRC discussion of 'automate' |
Date: |
Mon, 7 Aug 2006 10:21:44 +0200 |
User-agent: |
KMail/1.9.3 |
On Monday 07 August 2006 03:22, Nathaniel Smith wrote:
> > [SQL]
>
> Okay, I've spent a few minutes staring at this, and I give up :-).
> Can you break down what it does in English?
While I am personnally not yet convinced that this SQL statement works
correctly :), the basic idea I had yesterday while talking to Thomas Keller
on irc was the following:
Currently the code to determine branch heads basically does the following: It
first fetches all revisions carrying that branch tag and then calls
erase_ancestors on this list. This doesn't scale well, e.g. for the main nvm
branch the list of revisions feed to erase_ancestors becomes very large.
Now, while I am not familiar with the inner workings of erase_ancestors, I
suppose it's runtime is not linear in the size of it's argument list. So we
should recuce that list. Obviously, only those revisions qualify as branch
heads that either don't have children at all, or only have children carrying
different branch tags. Using this criterion (and having an indexed
revision_ancestry table) it should be possible to scrub the list easily
before feeding it to erase_ancestors.
However I am not sure whether this can be done using SQL, because all tags
(includung the branch tags) have to be validated before any reasoning can be
done based on their values.
Thomas
--
Thomas Moschny <address@hidden>
- [Monotone-devel] responses to some IRC discussion of 'automate', Nathaniel Smith, 2006/08/06
- Re: [Monotone-devel] responses to some IRC discussion of 'automate', Thomas Keller, 2006/08/06
- Re: [Monotone-devel] responses to some IRC discussion of 'automate', Nathaniel Smith, 2006/08/06
- Re: [Monotone-devel] responses to some IRC discussion of 'automate', Thomas Keller, 2006/08/07
- [Monotone-devel] Re: responses to some IRC discussion of 'automate', Bruce Stephens, 2006/08/07
- Re: [Monotone-devel] Re: responses to some IRC discussion of 'automate', Thomas Keller, 2006/08/07
- Re: [Monotone-devel] Re: responses to some IRC discussion of 'automate', Timothy Brownawell, 2006/08/07
- [Monotone-devel] Re: responses to some IRC discussion of 'automate', Bruce Stephens, 2006/08/07
- Re: [Monotone-devel] responses to some IRC discussion of 'automate', Timothy Brownawell, 2006/08/07
- Re: [Monotone-devel] responses to some IRC discussion of 'automate', Thomas Moschny, 2006/08/07
- Re: [Monotone-devel] responses to some IRC discussion of 'automate', Thomas Keller, 2006/08/07
- Re: [Monotone-devel] responses to some IRC discussion of 'automate', Nathaniel Smith, 2006/08/09