Does "svn update" download everything or just the diff patches?

I need to know a bit about subversion internals. Anyone know 开发者_如何转开发why actually gets transferred during a svn update? Say I have a huge file in the repo, with just a few lines changed. Will svn update download the whole file or just the changes?

Thanks!

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If you do a simple svn update you will get just the difference between your current REVISION and the HEAD revision on the server.

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Only changes is correct.

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Pablo is correct, plus it will also remove any stale locks. Suggest you read the friendly manual, it's very good.