Re: export to 8mm tape

In <3n8tru$b51_at_bingnet1.cc.binghamton.edu> bpanko_at_bingsuns.cc.binghamton.edu () writes:

We're doing something like this:

# 1. Create a pipe to export into

mknod expdat.dmp p
# 2. Read from the pipe, compress, and store on tape
# (/dev/rmt/0 should be the name of your tape device)
cat expdat.dmp | compress > /dev/rmt/0 &
# 3. Perform the actual export

exp system/manager full=y file=expdat.dmp buffer=64000

This is *significantly* faster than doing a straight export to tape, since much less data will be written to the *slow* tape device.

(Oracle tablespaces usually compress very well. Ours compress better than 10:1).

To import, you would do something like this:

# 1. Create a pipe to import from

mknod expdat.dmp p
# 2. Read from the tape, uncompress, and cat into the pipe
# (/dev/rmt/0 should be the name of your tape device)
cat /dev/rmt/0 | uncompress > expdat.dmp &
# 3. Perform the actual import

imp system/manager full=y file=expdat.dmp buffer=64000

You may want to play around with this to make sure you are comfortable with the export/import procedures *before* exporting and trying to reload the data. A good way to do this is to export just a few tables to a regular file, then try to reload it. If you do that, you can look at the export file to see what commands import is executing.

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