On 6/6/19 6:50 AM, Karsten Hilbert wrote:
Now that it is established that CREATE DATABASE does not
verify checksums on the template I have a followup question.
The current canonical solution (?) for verifying checksums in
an existing database is, to may understanding, to pg_dump it
(to /dev/null, perhaps):
pg_dump --username=... --dbname=... --compress=0 --no-sync --format=custom --file=/dev/null
as that will read and verify all blocks related to the dump
of that database.
The question I have is:
The above works with the existing cluster, but would you not also want
to verify that the blocks written to on the new cluster also are good?
One will be tempted to include options to speed up the
process, say:
--data-only
which would not output schema definitions. I wonder, however,
whether doing so would allow pg_dump to skip some reads into
the catalog tables, thereby, perhaps not detecting some
corruption in those ?
This question would apply to the following list of options as
far as I can see:
#--no-acl
#--no-comments
#--no-publications
#--no-subscriptions
#--no-security-label
Is my assumption wrong ?
Not sure, though it would seem to me including the above is a relatively
small incremental cost to the overall dump, assuming a data set of any
size greater then small.
I don't really expect to just be handed a full answer (unless
someone easily knows offhand) - however, I don't really know
where to look for it. Pointers would be helpful.
Is the only way to know reading the source or suitable
server logs and compare queries between runs with/without
said options ?
Thanks,
Karsten
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Adrian Klaver
adrian.klaver@xxxxxxxxxxx
