Downgrading vertica version

sathya_jith

Hello All,

Can we downgrade the Vertica version?
My PROD machine is running in 'Vertica Analytic Database v8.1.1-5' but my DEV is in 'Vertica Analytic Database v8.1.1-7'. I want to downgrade my DEV machine to 'v8.1.1-5'. If yes, how?

Thank you,

Jim_Knicely

Hi,

Downgrade installations are not supported.

See:
https://my.vertica.com/docs/8.1.x/HTML/index.htm#Authoring/InstallationGuide/InstallingVertica/InstallingVerticaUsingTheCommandLine.htm

Why? Because with each upgrade/hot fix, there are changes (i.e. to the catalog) that are irreversible.

How big is your DEV database? Is it a single node?

sathya_jith

Hi Jim,

Thank you for your info. Dev database is pretty big. It has 3 nodes.
So what do you suggest on downgrading? Uninstall and reinstall?

Jim_Knicely

Is upgrading PROD to 8.1.1.7 out of the question? For your reference, I attached a file that lists the hot fixes in Vertica 8.1.1.6 and 8.1.1.7.

If not, I can think of a few options (First, take a FULL back up of DEV prior to doing anything...):

Option 1: Create a new DEV cluster using 8.1.1.5 and then copy the data from the old one to the new one using replication (if it works between these version) or COPY FROM VERTICA/EXPORT TO VERTICA feature

Option 2: Export the catalog (to get DDL), export ALL table data to files, drop the old database, uninstall 8.1.17, install 8.1.1.5, create the database, run the catalog script, load the data from files

Option 3: Open a ticket with support and ask if you can export objects (i.e. schemas) from an 8.1.1.7 database and restore them to a 8.1.1.5 database. This should work.

Option 4: Open a ticket with support and ask if a FULL backup from 8.1.17 can be restored to an 8.1.16 database (I highly doubt this is possible).

Option 5: Drop the database, uninstall 8.1.1.5, install 8.1.17, create the database and then load it from PROD as you would normally.

But please take a back up before you try anything if you have the space!

Thanks!

sathya_jith

Hi Jim, thank you for your inputs. Much appreciated.

Jim_Knicely

No problem!

Please let us (the community) know later how you ultimately resolved your issue!

Ben_Vandiver

While downgrade is not supported, downgrade by a hotfix or two is less likely to get yourself in trouble (downgrade of a major/minor/SP is highly likely to get you in trouble).
Before playing games, I would absolutely take an in-place backup:
https://my.vertica.com/docs/8.1.x/HTML/index.htm#Authoring/AdministratorsGuide/BackupRestore/UsingHardFileLinkLocalBackups.htm?TocPath=Administrator's%20Guide|Backing%20Up%20and%20Restoring%20the%20Database|_____20

Jim_Knicely

@sathya_jith - Fyi: I just got word that there is an issue with Vertica 8.1.1-6, 8.1.1-7 and 8.1.1-8 where you may notice a sudden drop in performance after database is UP for few days. It is recommended to upgrade to 8.1.1-9 as it fixes that performance issue along with another bug that made recovery from scratch single threaded.

Jim_Knicely

@sathya_jith - See: https://forum.vertica.com/discussion/239197/vertica-8-1-1-6#latest

sathya_jith

thanks a lot for your update @Jim_Knicely .