Re: ZFS snapshots - to use pg_start_backup() and pg_stop_backup() or no?

On Wed, Sep 11, 2013 at 8:00 PM, Gregory Haase <haaseg(at)onefreevoice(dot)com>wrote:

> Typically how fast is a crash recovery for a ~1TB database with heavy OTLP
> load? Are we talking several seconds, several minutes, several hours?
>

This will depend on how fast your file system is, how frequent your
checkpoints are (this is tunable), and how many WAL segments you allow
(also tunable). The trade off is if you do less frequent checkpointing and
have more WAL segments, you can boost your write speeds, but the cost is
longer recovery. Ideally you want to tune the number of WAL segments to be
just the right number to keep from forcing checkpoints before your
configured timeout to run a checkpoint, and you configure your checkpoint
time to whatever duration of time you need to keep your recovery time as
short as you want.