On 10/19/19 4:17 PM, Julie Nishimura wrote:
Thank you, Thomas. Do you know if it is safe to replicate 9.6.2
(smaller) db to 9.6.15 (larger capacity) using pg_basebackup? Would it
be considered as an upgrade?
pg_basebackup backups an entire Postgres cluster which will be many
databases. So when you say db do mean a Postgres cluster or an
individual database?
------------------------------------------------------------------------
*From:* Tomas Vondra <tomas.vondra@xxxxxxxxxxxxxxx>
*Sent:* Saturday, October 19, 2019 5:44 AM
*To:* Julie Nishimura <juliezain@xxxxxxxxxxx>
*Cc:* pgsql-general@xxxxxxxxxxxxxxxxxxxx
<pgsql-general@xxxxxxxxxxxxxxxxxxxx>; pgsql-general
<pgsql-general@xxxxxxxxxxxxxx>
*Subject:* Re: releasing space
On Thu, Oct 17, 2019 at 05:20:09PM +0000, Julie Nishimura wrote:
Hello everybody, We are running PostgreSQL 9.6.2 cluster master ->
standby (streaming replication). 22 tb of space (constantly struggling
with the space, pruning the old data, but not fast enough). The biggest
db takes 16 tb. So, we've copied it to another server, and now we would
like to delete it from our original source, to free up the space. What
would be the right approach for this? Just issue drop database command
(16tb). How long it might take? Should we do it gradually (drop biggest
tables first)? Any suggestions? Caveats?
Generally speaking, DROP DATABASE simply recursively drops all the
various objects - indexes, tables, etc. It mostly just deleting the
files, which should not be very expensive (we certainly don't need to
delete all the data or anything), but there's certain number of I/O
involved. But it does depend on the OS / filesystem / hardware if that's
an issue.
So if you want to be on the safe side, you can drop the objects one by
one, with a bit of delay between them, to throttle the I/O a bit.
FWIW the latest minor release for 9.6 is 9.6.15, you're 13 minor
versions (~30 months) of fixes behind. You might want to consider
upgrading ...
--
Tomas Vondra http://www.2ndQuadrant.com
PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services
--
Adrian Klaver
adrian.klaver@xxxxxxxxxxx
