True definition of deleting data

tannerpokego

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Aug 24, 2017
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I had a to take a test at work today on salesforce and one of the questions asked what happened to the data when it was removed from an object. Basically what happens is it is 'deleted' and moved to a recovery bin to be recovered 15 days. I ended up getting this question wrong because I didn't consider the data deleted. What defines something as deleted? I thought since the data was only moved to a recovery bin and still recoverable it was not concidered deleted also on that the data would not be deallocated or and able to be partially or fully written over in the drive since there is a recovery option so that wouldn't make sense. Would that data not just be considered 'Moved' or reallocated? Does a button that says delete that just moves data make something deleted?
 
Solution
What the Salesforce CRM application does is completely different than what the Windows OS does.

Salesforce is a database, not regular files on your PC.
A row deleted from that may well be 'gone' after 15 days.

Also, those 'tests' are often wildly incorrect as to what the 'right answer' is.
Some years ago, the HR director at our company purchased a Windows/Office test application, to evaluate new employees.

Me, being the lead MS software developer, got to evaluate this 'test'.
One of the questions was "How do you create a Shortcut on the Desktop?"

Of course, there are 7 different ways to do this, all equally easy. But if you did not choose their one specific method....wrong.
I went back to the HR director and...
Typically when data is "deleted" by hitting delete it merely changes the first letter or 2 of the file name so that it won't show up natively. I wouldn't consider something deleted until the remaining file has been altered via a "shredding" program
 
What the Salesforce CRM application does is completely different than what the Windows OS does.

Salesforce is a database, not regular files on your PC.
A row deleted from that may well be 'gone' after 15 days.

Also, those 'tests' are often wildly incorrect as to what the 'right answer' is.
Some years ago, the HR director at our company purchased a Windows/Office test application, to evaluate new employees.

Me, being the lead MS software developer, got to evaluate this 'test'.
One of the questions was "How do you create a Shortcut on the Desktop?"

Of course, there are 7 different ways to do this, all equally easy. But if you did not choose their one specific method....wrong.
I went back to the HR director and told him..."You just wasted a buttload of company money"
 
Solution


Something is only truly deleted if every single bit of information has been overwritten by something else. Then it is like the old data never existed.
 

Information cannot be destroyed.
https://en.wikipedia.org/wiki/Black_hole_information_paradox

It can only be transformed. If you have a reverse transformation available, it can be recovered. It may be prohibitively expense to do so, but it's still possible.

https://www.youtube.com/watch?v=_dbnH-BBSNo

In other words, nothing is ever truly deleted.

Now, if Salesforce wishes to define "deletion" as "removed from the database", then yeah the answer is whatever their definition says it is.
 
All the data used by or through windows has an address. When something is 'deleted' and moved to the bin, it's just moved. Windows assigns the addresses of the data to the bin-folder. They'll sit in the bin for as long as they do, depending on the bins settings. If the bin is set for 14 days, windows releases the addresses of the data, and assigns them to whatever is needing to be saved next. So on day 15, it's pot-luck, possible recovery. If the bins settings are for daily removal, after 15 days, chances are extremely poor that you'll get any recovery as some blocks might have seen multiple overwrites.