From https://www.postgresql.org/docs/9.1/static/protocol-message-formats.html:

  Bind (F)

  ...

  After the last parameter, the following fields appear:

  Int16

    The number of result-column format codes that follow (denoted R
    below). This can be zero to indicate that there are no result
    columns or that the result columns should all use the default
    format (text); or one, in which case the specified format code is
    applied to all result columns (if any); or it can equal the actual
    number of result columns of the query.

  Int16[R]

    The result-column format codes. Each must presently be zero (text)
    or one (binary).

Also fix testBinaryTypes test:

- force binary by setting prepareThreshold to -1
- handle REAL type as float

Without the fix the corrected test testBinaryTypes fails:

  05:25:02 21:55:02.666 org.h2.test.unit.TestPgServer Expected: 12345678 actual: 825373492
  Exception in thread "main" java.lang.AssertionError: Expected: 12345678 actual: 825373492
      at org.h2.test.TestBase.fail(TestBase.java:464)
      at org.h2.test.TestBase.assertEquals(TestBase.java:617)
      at org.h2.test.unit.TestPgServer.testBinaryTypes(TestPgServer.java:404)
      at org.h2.test.unit.TestPgServer.test(TestPgServer.java:51)
      at org.h2.test.unit.TestPgServer.main(TestPgServer.java:41)