Re: Mercurial vs. Git – Repository size (was: Mercurial media coverage: Phoronix)

[Stanimir Stamenkov]

Thu, 11 Feb 2021 23:37:57 +0200, /Stanimir Stamenkov/:
> Thu, 11 Feb 2021 11:46:52 +0100, /Marcus Harnisch/:
> 
>> Rafaël's FOSDEM (and linux.conf.au?) presentation has received some 
>> media coverage.
>>
>> https://www.phoronix.com/scan.php?page=news_item&px=Mercurial-More-Rust-2021 
> 
> While Mercurial may excel at some performance scenarios and is actively 
> improving on it, I wonder if there are efforts to improve on repository 
> sizes as it seems to me it is one of the main reasons Git gets chosen 
> over Mercurial (if we ignore the fact Git just have wider adoption, 
> integration, and richer tooling available).

So I've watched: https://youtu.be/MBQLL3uCQ4I

At the end (44:20) it mentions "non-Rust development" and lists:

* Sparse-revlog (up to 99 % reduction of manifest size)
* New revlog format (fewer files, better information)

Looks quite promising.

> For example, I see this given as one of the main reasons for OpenJDK 
> moving from Mercurial to Git 
> <https://openjdk.java.net/jeps/357#Motivation>:
> 
>> There are three primary reasons for migrating to Git:
>>
>>  1. Size of version control system metadata
>>
>> Initial prototypes of converted repositories show a significant 
>> reduction in the size of the version control metadata. For example, 
>> the .git directory of the jdk/jdk repository is approximately 300 MB 
>> with Git and the .hg directory is around 1.2 GB with Mercurial, 
>> depending on the Mercurial version being used.

-- 
Stanimir