Document Additional Upgrade Considerations
Adds an "Additional Considerations" section to the PGO v4 to PGO v5
upgrade guide, which specifically describes the potential need to
perform additional steps when migrating between OS version (e.g. from
CentOS 7 to CentOS 8 or from UBI 7 to UBI 8).
Issue: [sc-12181]
@@ -440,3 +440,14 @@ spec:
```
Your upgrade is now complete! For more information on how to use PGO v5, we recommend reading through the [PGO v5 tutorial]({{< relref "tutorial/_index.md" >}}).
+
+## Additional Considerations
+
+Upgrading to PGO v5 may result in a base image upgrade from EL-7 (UBI / CentOS) to EL-8
+(UBI / CentOS). Based on the contents of your Postgres database, you may need to perform
+additional steps.
+
+Due to changes in the GNU C library (`glibc`) in EL-8, you may need to reindex certain indexes in
+your Postgres cluster. For more information, please read the
+[PostgreSQL Wiki on Locale Data Changes](https://wiki.postgresql.org/wiki/Locale_data_changes), how
+you can determine if your indexes are affected, and how to fix them.
