I have an existing postgres database with the database "testdb" and the database schema testdbschema".
If I use the default persistence.xml configuration of RESOURCE_LOCAL the following property is working:
<property name="javax.persistence.jdbc.url" value="jdbc:postgresql://server:port/testdb?currentSchema=testdbschema" /> 
I want to configure my database connection within my web.xml as a data-source. Everything is working well, except the configuration of the database schema.
Here is my web.xml configuration:
<data-source>
    <name>java:global/myapp</name>
    <class-name>org.postgresql.ds.PGSimpleDataSource</class-name>
    <server-name>127.0.0.1</server-name>
    <port-number>5432</port-number>
    <database-name>testdb</database-name> 
    <user>postgres</user>
    <password>postgres</password>
</data-source>
Do you now how can I configure my db schema name here?
The configuration via testdb?currentSchema=testdbschema did not work for me and I get a database not found failure.