49.7. Logical Decoding Output Writers
  It is possible to add more output methods for logical decoding.
    For details, see
  
   src/backend/replication/logical/logicalfuncs.c
  
  .
    Essentially, three functions need to be provided: one to read WAL, one to
    prepare writing output, and one to write the output
    (see
  
   Section 49.6.5
  
  ).