1. upload 'example.txt' to a temporary filename on the host, like 'example_temp.txt'
2. delete the remote 'example.txt' file
3. rename the remote 'example_temp.txt' file to 'example.txt'
If the file in question is a large file, the advantage is that the time the file is 'missing' or incomplete is only the delay between steps 2 & 3. Depending on server OS, step 2 may not be needed anyway.
Many FTP clients do this automatically for all uploads, using the STOU command, followed by a rename. (thus eliminating virtually ANY delay). Of course, there is no real need for an STOU command, as the client could generate a unique temporary filename on its own.
I can't seem to find how to do enable this with WinSCP.
In my case, I have some clients who use flat file databases. If a 1mb database takes 5 seconds to upload, then web users who visit during this 5 seconds may get strange results if the file is used for generating, say... anything.
It's a fairly common feature, and may already be present in WinSCP. If so, please tell me where.