Re: Using RSYNC for replication?

>>>>> "TL" == Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> writes:

TL> A final note is that I doubt this would be very efficient: wouldn't
TL> rsync have to ship entire table files (and entire WAL log files) for
TL> even the most piddling change?

No, rsync is smart that way. It checksums hunks of the files, and
sends only the parts that change. I did a test and the first rsync
took me 4 hours. The second one the next day took about 1.5 hours.

I was moving the data to another box, and the time to
dump/restore/analyze the tables was enormous. Using rsync made it
faster. First I did the rsync live (4 hours), then shut down the
source postmaster, did the rsync again (only 1 hour) and brought up
the new server. Downtime was 1 hour rather than 8.

However for backup purposes, it makes no sense.

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