With iOS-5 UITableView allowsmultipleselection, is there any quick way with good performance to select (and highlighted) all rows? I'm talking about more than thousands rows data of fetchedResultsController. 

I've tried with selectRowAtIndexPath:animated loop, and seems it's not a good idea for huge dataset.

Also I've discovered if deselect all rows performance will be better with tableview reloadData than deselectRowAtIndexPath:animated: inside a loop. Is this the safe way to clear selections?

Thanks


Question: Combine multiple unix commands into one output
Answer: Here's another way to do it (assuming you're running bash, which you probably are):

cat &lt;(bzgrep ...) &lt;(grep ...)


Here bash is transparently feeding the output of the bzgrep and grep commands into cat as if they were files (and they sort of are under the hood, details in url at the bottom).

In your particular case I'd recommend Phil's solution, but the above is a good trick to keep in your bag.

If you're interested, you can read more here: http://www.tldp.org/LDP/abs/html/process-sub.html