We would like to use the schema property in HikariCP but the current version in DXP 7.2 doesn't appear to support this.
Based off https://github.com/liferay/liferay-portal/blob/7.2.x/lib/versions-complete.xml#L5959-L5970, it looks like DXP 7.2 uses HikariCP 2.6.3:
When we attempt to configure an external database via JDBC using portal-ext.properties entries, we receive an error setting the "schema" property.
Per the HikariCP documentation, "schema" is one of the parameters we can set.
We want to configure our applications to use accounts that are not the schema owner of the custom tables. Configuring the JDBC connection to use that secondary account and setting the schema property is expected to prefix all our queries correctly identify the schema owner. Example SQL to illustrate this:
Looking at the HikariCP code, that property has been in the HikariConfig since 2017. I believe that is version 2.7.0. We request that Liferay update this library to version 2.7.0 or higher.