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Vaishnavi M
Vaishnavi M

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Git Rebase vs Git Merge: A Comprehensive Guide

Git, a distributed version control system, offers a variety of ways developers can integrate changes from one branch into another: git merge and git rebase being two of the most commonly used strategies. Understanding the differences, benefits, and best practices of both can greatly enhance your Git workflow efficiency.

Understanding Git Merge

Think of git merge as a handshake between two branches. The git merge command integrates changes from one branch into another. It takes the contents of a source branch and integrates it with the target branch. If the histories of both branches have diverged, Git creates a new merge commit to combine the histories, preserving the history as it happened.

Consider two branches, feature and master:

A---B---C feature
 /
D---E---F---G master
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Merging feature into master would result in:

A---B---C feature
 /         \
D---E---F---G---H master
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The master branch now includes a new commit H that represents the merge commit, preserving the history of both branches as they happened.

Understanding Git Rebase

git rebase is a command that allows you to integrate changes from one branch into another, similar to git merge. But it works in a different way. Let's consider git rebase as a painting process. Imagine the master branch as a wall and the feature branch as an artist. Initially, the master branch (the wall) is painted first. The feature branch (the artist) then comes in and adds their work on top of the master branch's work.

However, if the original painting (the master branch) is updated, the artist (the feature branch) would temporarily remove their painting, allow the wall to be updated, and then add their painting back on top of the updated wall. This is essentially what happens in git rebase.

git rebase takes the changes made in the feature branch and reapplies them onto the master branch, effectively creating a new base for the feature branch and rewriting history. This results in a more linear and clean commit history.

Consider again two branches, feature and master:

A---B---C feature
 /
D---E---F---G master
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Rebasing feature onto master would give:

D---E---F---G master
             \
              A'---B'---C' feature
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Commits A, B, and C are reapplied onto master, creating new commits A', B', and C'.

Comparing Git Merge and Git Rebase

Benefits and Use Cases

Preserving History: Git merge preserves history as it happened, including the time and order of all commits, while Git rebase can rewrite and clean up history, making it more linear and comprehensible. This can be beneficial when you want to understand the development process.

Conflict Resolution: When merging, conflicts need to be resolved once during the merge commit. However, during a rebase, you may have to resolve conflicts for each commit being reapplied. This can become tedious if many commits have similar conflicts.
Best Practices

Rebase for Local Cleanup: Rebase can be used to clean up local, in-progress features. By periodically performing an interactive rebase, you can ensure each commit in your feature is focused and meaningful.

Merge for Public Commits: Once you have shared your branch with others, it is best practice to use merge. Rebase could potentially rewrite the commit history and create confusion for other developers.
Avoid Rebasing Public Branches: Rebasing a public branch that others have based work on is a bad practice as it alters the commit history. This can cause confusion and further conflicts for other developers.

Conclusion

Both git merge and git rebase are powerful tools for integrating changes from one branch into another. They serve different purposes and are used in different scenarios. It's essential to understand the implications of each and choose the right tool for the right situation.

git merge is great for combining code from two different branches and preserving the exact historical timeline of commits. On the other hand, git rebase is excellent for making your feature branch up to date with the latest code from the master branch, keeping the history of your feature branch clean and making it appear as if the work happened sequentially.

In both cases, conflicts can arise and need to be resolved manually. But remember, once you've shared your branch with others, it's a best practice to use git merge to avoid rewriting public commit history.

Top comments (5)

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raulpenate profile image
The Eagle 🦅

Thanks for the article. Just to confirm that I understand it:

  • Merge asks what we should do when there is a conflict between changes.
  • Rebase removes the previous changes and applies the new changes on top, whether or not there is a conflict.

Is there an opposite operation to rebase?

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vaishnavi_m_1194 profile image
Vaishnavi M

Great question!
Actually, rebase doesn't remove previous changes, it rewrites the commit history by applying your changes on top of the target branch. If you want to preserve the commit history instead, you'd use merge, which keeps both branches' changes and commits intact. There's no 'opposite' to rebase, but merge would be the alternative for keeping history.

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kiri991 profile image
kiri991

I found the discussion on Git rebase vs. Git merge insightful, especially for managing complex development workflows. For those interested in exploring more about different tools and strategies, you might also want to check out the diverse range of online gaming services available. You can explore top options and find the best fit for your needs at topxpartners.in/. This site provides valuable insights into various gaming options that can enhance your experience and offer exciting new opportunities.

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jangelodev profile image
João Angelo

Hi Vaishnavi M,
Top, very nice and helpful !
Thanks for sharing.

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martinbaun profile image
Martin Baun

Understanding and using both concepts when appropriate is the way.