My computer is not powerful at all so Atom is obviously slow as hell and lags all the time, at first I thought I improved my typing skills because I was typing faster than the editor was displaying the characters, but that was obviously not the case. Most Atom users — or at least the most active users — use rMBPs with i7 CPUs and (maybe?) 16GB of RAM, I don't want to buy a computer like that just to use a code editor like this, I would do it for an IDE though; and even if I had a computer like this I would not want to give most of its resources to the code editor when there are more important things to spend the CPU / RAM on.
If your intention is to open a database dump then use a different tool, a proper log viewer or something like that, I don't even understand why would you want to use a code editor — even with good performance — to inspect a DB dump in the first place.
Database dump and log files are just good example of potentially big text files. They should be usable in any text editor. Not looking at the issue is not a good way to build software.
Atom is for writing code, not viewing logs. We have tail and syslog and a thousand other tools for that.
"Atom - A hackable text editor"