The best way to delete a record from a file?

Yeah I realized that afterwards, but dident bother posting about it. So, after all, I still don't get how 'moving' is meant to work the same way as 'copying' here ???

Just copy and truncate the end of the file and you've basically "moved" the data. Or you can just zero it out. Either way.

Yeah, but then you have two copies and by truncating you just remove the copy you just made o_0

The way I see it is that to physically 'move' the data you need to remove the space where the original data was stored at. The only way I know how to do this is by overwriting the rest of the file from the place where the data was removed.

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Originally Posted by mike_g

Yeah, but then you have two copies and by truncating you just remove the copy you just made o_0

The way I see it is that to physically 'move' the data you need to remove the space where the original data was stored at. The only way I know how to do this is by overwriting the rest of the file from the place where the data was removed.

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If the old data is past the end of file and therefore not accessible, it is in essence, deleted.

Yeah I get that part, but it does not explain the process of moving it.

On the contrary, it does.
Let's say we have 5 records, 1, 2, 3, 4 and 5. We delete record 3. So we copy the from record 4 and 5 downwards, so we overwrite record 3. So we copy record 4 and 5 and it thus becomes:
1, 2, 4, 5, 5. Then we truncate the end to remove the extra 5 and it becomes 1, 2, 4, 5. Makes sense?

Lol, well I knew that too! I just explained it as the only way i saw this being possible. With a large database thats getting updated all the time thats going to be a hell of a lot slower than just marking a character to signal an entry as deleted. Then you would only need to rewrite the data once in a while instead.

Indeed, and that's why the delete flag is preferable!

Who said they needed to be in order? Who said they were in order to start with?

None, but then again, no one said they do not need to.
So it's just to pick an applicable solution.

For most things in a computer: Move = Copy + Delete
Unless you want to physically cut a piece of the hard drive surface away and glue it onto a new location on the platter; then it would truly be considered a Move. ;)