|No such thing as a small change|
Re^9: selecting columns from a tab-separated-values fileby BrowserUk (Pope)
|on Jan 24, 2013 at 09:01 UTC||Need Help??|
Rerunning with 5.16 yielded a runtime of 60 seconds.
Conclusion: With 384GB of ram; your (relatively) tiny 10e6 lines test file is being read from system file cache, hence effectively disguising the disk IO costs.
If your 80GB file fits in cache and will always be there when you need to do this; you can ignore the effects of disk.
Otherwise ... you need to re-run all your testing using the real file and having flushed the cache before each test.
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