Any way to index multiple columns?

[Jonathan Feinberg]

Is there any way to cause the OpenJPA schema builder to emit an index across 
multiple columns? My attempt,
 @Column(columnDefinition = "bytea")
 @Index(name = "i_owner_md5", columnNames = { "owner_id, md5" })
 public byte[] getMd5()
 {
  return md5;
 }
is silently misinterpreted, in that only the annotated field (md5) gets indexed.

Thanks,
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