Comment 2 for bug 456077

Two things occured here:

You branched over HTTP which means it did not stream. And MYSql need to
upgrade to the 2a format, which improves memory usage and performance.
The branching performance of very large projects (like mysql5) with
older formats cannot be comprehensively improved because the amount of
effort is quadratic.

If you do 'bzr lp-login' before branching you will get a streaming
branch which is a lot faster and should use less memory.

If the MYSql branches are upgraded, then things will get better still.

 status invalid

I will note that we have significant memory improvements in the works
for 2.1 and there are bugs open on that.