How do you issue a single JDBC call to Postgres which includes 2 select statements? The two select statements select from different sets of tables and return two different result sets - so cannot be union-ed. The goal is to ensure that what is read from the database is a consistent snapshot of data in the tables at the instant the selects are issues. If two separate select statements are issued, there is a chance of some data getting updated after the first select and before the second one.
Look like java.sql.Statement's addBatch() and executeBatch() can not be used - this can only be used for updates. Attempting to use it with selects causes a PSQLException with message "A result was returned when none was expected." on executeBatch().
