2009-04-28 15:30:39 UTC
I am on ASE15 on Solaris. The manual says "If the device file already
exists, Backup Server overwrites it; it does not truncate it. For example,
suppose you dump a database to a device file and the device file becomes
10MB. If the next dump of the database to that device is smaller, the device
file is still 10MB." In my experience this has been true; for example one
time when I increased the number of stripes, resulting in more (but smaller)
dump files, each "new" dump file was smaller than before, but the "existing"
dump files did not shrink. Granted, this might have been on a pre-ASE15
server, I forget. But the ASE15 manual seems unambiguous.
So I was surprised recently when I started using compression, and it
appeared that the dump file actually shrank in place. I don't mind this
behavior, but I was wondering whether this should be expected to happen.