-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 Jeff Davis wrote: > On Mon, 2006-08-07 at 14:51 -0500, Ron Johnson wrote: > >> What would be darned useful (but only, I think, with heavy usage of >> tablespaces) is: >> $ pg_tapedump /some/database /dev/st0,/dev/st1,/dev/st2,/dev/st3 > > I must be missing something. What is stopping you from doing something > along the lines of: Missing nothing. :) > // mux.script psuedocode > // X is the size of a stripe of data > top: > read X bytes from stdin or exit if EOF > asynchronously write those X bytes to /dev/st0 > read X bytes from stdin or exit if EOF > asynchronously write those X bytes to /dev/st1 > goto top Python queues and threads would make that very simple. Master thread reads from pg_dump pipe, passing X bytes to a queue, and each thread performs this loop: - read from queue - synchronously write to /dev/stN > And then make an inverse script called demux.script. > > Then: > $ pg_dump somedatabase | gzip -c | mux.script > To restore: > $ demux.script | gunzip -c | psql somedatabase > > Would that work? Obviously you'd have to document the process well to > make sure the someone didn't get confused 12 months later trying to > restore. The disk system would have to be fast enough to keep all X tape drives full. Depending on the speed of the tape systems and disk system, having X "threads" reading from the database/writing to tape, all at the same time is much faster. > You may have to do something a little more sophisticated to make it work > more generally, like adding header information to each tape that says "I > am the 2nd tape of 3". Depending on the capabilities of your tape drive, CRC, error checking, load-next-tape, etc, etc. - -- Ron Johnson, Jr. Jefferson LA USA Is "common sense" really valid? For example, it is "common sense" to white-power racists that whites are superior to blacks, and that those with brown skins are mud people. However, that "common sense" is obviously wrong. -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.3 (GNU/Linux) Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org iD8DBQFE17XRS9HxQb37XmcRApdSAKCv390n8/eQxdodF3D6PQGBvyUSUACfR5NO ZpL8Ac6RMHQRHNqCEb8Grwo= =nrzR -----END PGP SIGNATURE-----
