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I currently have a Postgresql v9.3.3 running on AWS RDS. I've learned that if I upgrade Postgres to 9.3.5 that I can create read replicas.

However, I am afraid of losing data. Can I just select "modify" from the console "instance actions" section and upgrade to 9.3.5 without losing any data; or do I need to do something special?

nu everest
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    Upgrading from 9.3.3 to 9.3.5 should be a simple instance restart. It's on-disk compatible. Unless RDS does something crazy it should be trivial. – Craig Ringer Dec 28 '14 at 06:40

3 Answers3

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You're fine - if there is a possible data loss AWS wouldn't provide a single click update. As this is only a minor version update it is pretty easy to upgrade without any problems.

Osterjour
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What Osterjour said is only partly true. There is almost no way to lose data, especially if configured in multi-az.

  1. Minor upgrades such as versions etc. will not cause downtime.
  2. Adding read-replicas will not cause downtime, but I/O will be suspended briefly while the snapshot is being made and synchronized to the new read replica.
  3. Modifying the instance type will cause downtime, even with multi-az.
Marc Young
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To avoid losing data you would have to come up with a data integrity validation strategy prior to upgrade and post upgrade even if is minor upgrade.

From experience= i migrated postgreSQL 9.6.6 to 9.6.9 (minor upgrade). Small validation and the downtime was 12 minutes due to manual snapshot and automatic pre-upgrade and post-upgrade performed by AWS RDS. In general terms it was good and everything was smooth.

Recommendation= test. Do dry-runs many. and pay attention to the DB load plus the DB extensions. 

https://docs.aws.amazon.com/AmazonRDS/latest/UserGuide/USER_UpgradeDBInstance.PostgreSQL.html

Check AWS official Doc. AWS RDS Upgrades

Please Let us know after 4 years what you decided and how did it go?

Andre Leon Rangel
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  • If you do a manual snapshot not long before an upgrade it can reduce the work required for any automatic snapshots taken during the upgrade. This is because snapshots are incremental. – Tim Jun 27 '19 at 07:33