Re: what is a snapshot?

From: Philip Oakley <philipoakley@iee.org>
Date: Jun 19, 2016, 15:20 UTC
Message-ID: <F6172B8DA802476C863849DEA02684A7@PhilipOakley>
In-Reply-To: <CAHWPVgMWeHoD5vTiFJ1gsm2hS74LK7j4npVVbOZeR43cX3qWXw@mail.gmail.com>

From: "Ovatta Bianca" <ovattabianca@gmail.com>

Show 6 quoted lines

>I read in every comparison of git vs other version control systems,
> that git does not record differences but takes "snapshots"
> I was wondering what a "snapshot" is ? Does git store at every commit
> the entire files which have been modified even if only a few bytes
> were changed out of a large file?
>

A snaphot is like a tar or zip of all your tracked files. This means it is easier to determine (compared to lots of diffs) the current content.

Keeping all the snapshots as separate loose items, when the majority of their content is unchanged would be very inefficient, so git then uses, at the right time, an efficient (and obviously lossless) compression technique to 'zip' all the snapshots together so that the final repository is 'packed'. The overall effect is a very efficient storage scheme.

There are some good explanations on the web, such as the https://git-scm.com/book/en/v2/Git-Internals-Plumbing-and-Porcelain though you may want to scan from the beginning ;-)

--
 Philip