http://benwerd.com/2009/04/facebook-has-no-need-for-deleting-data/ Mon, 15 Mar 2010 19:24:46 +0000 http://wordpress.org/?v=2.8.4 hourly 1 http://benwerd.com/2009/04/facebook-has-no-need-for-deleting-data/comment-page-1/#comment-20715 Niall Kennedy Thu, 09 Apr 2009 22:50:27 +0000 http://benwerd.com/2009/04/facebook-has-no-need-for-deleting-data/#comment-20715 Facebook has said photo removal results in photo index deletion but not a deletion from the backend store. There is no reference to what is in between disk marker 400 and 822, for example, but the data is still there. Their past presentations mention deletes are rare occurrence and therefore sequential writes make the most sense. Facebook has said photo removal results in photo index deletion but not a deletion from the backend store. There is no reference to what is in between disk marker 400 and 822, for example, but the data is still there. Their past presentations mention deletes are rare occurrence and therefore sequential writes make the most sense.

]]> http://benwerd.com/2009/04/facebook-has-no-need-for-deleting-data/comment-page-1/#comment-20249 Paul Mon, 06 Apr 2009 14:23:02 +0000 http://benwerd.com/2009/04/facebook-has-no-need-for-deleting-data/#comment-20249 When dealing with lots of data rows deleting can be very resource intensive. Even on an Oracle database the slot where you delete data from doesn't really get deleted, unless it is needed again, much like disk files. If files only really need to be deleted by legal request then it is much better to write a fast filesystem/database with a slow search-and-destroy delete function, rather than deleting constantly and instantly. When dealing with lots of data rows deleting can be very resource intensive. Even on an Oracle database the slot where you delete data from doesn’t really get deleted, unless it is needed again, much like disk files.
If files only really need to be deleted by legal request then it is much better to write a fast filesystem/database with a slow search-and-destroy delete function, rather than deleting constantly and instantly.

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