Thread: V12 to V16 Upgrade -- does size matters?
Hi,
Does size matter when doing the upgrade?
Just noted the non-PROD database is 20G and the PROD one is around 500G.
Does the size of the database affect how long the upgrade will finish? Especially when running the ANALYZE post-upgrade.
FYI, more than half of the 500G are pg_toast.
On Mon, Feb 24, 2025 at 11:48 PM Edwin UY <edwin.uy@gmail.com> wrote:
Hi,Does size matter when doing the upgrade?Just noted the non-PROD database is 20G and the PROD one is around 500G.Does the size of the database affect how long the upgrade will finish?
Yes, if you run standard pg_upgrade. (It's got to copy all the files to the new directory.)
No, if you run pg_upgrade with the --link or --clone options.
520GB isn't that much, though.
Beware, though: using the --link and --clone options don't let you revert after starting the new instance.
Especially when running the ANALYZE post-upgrade.
Maybe, or maybe not. Bigger tables take longer to ANALYZE. But if there are lots of CPUs and you've got lots of medium-sized tables, then --jobs=$(nproc) will chew through them much faster.
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