Problem Definition
Currently, it is have stated that:
PostgreSQL 7.2 and later require a schema to be specified in the <schema-name/> element. If your PostgreSQL database uses the default 'public' schema, this should be specified in the <schema-name/> element as shown below. Ensure that your database schema name is lower-case, as JIRA cannot work with PostgreSQL databases whose schema names contain upper-case characters.
From the official PSQL documentation, when using a schema other than public, DBA needs to update the search_path to include the new schema.
Suggested Solution
Update the documentation to include this information.
Note
A bug that is affected by this is JRASERVER-64886.