title: How to map a postgresql pgarray type to an array type of flink
body: <p>i'm using flink (JDBCInputFormat) to read data out of a postgresql database in a distributed way. JDBCInputFormat requires to specify TypeInformation for all database columns. Postgresql is using special array type PgArray. If I try to use BasicArrayTypeInfo I allways got "java.lang.ClassCastException: org.postgresql.jdbc.PgArray cannot be cast to [Ljava.lang.String;".
  Any ideas how to solve it?</p>
  
  <p>Thanks in advance,
  Hannes</p>