PostgreSQL

F.40. test_decoding
Prev	Up	Appendix F. Additional Supplied Modules	Home	Next

F.40. test_decoding

test_decoding is an example of a logical decoding output plugin. It doesn’t do anything especially useful, but can serve as a starting point for developing your own output plugin.

test_decoding receives WAL through the logical decoding mechanism and decodes it into text representations of the operations performed.

Typical output from this plugin, used over the SQL logical decoding interface, might be:

postgres=# SELECT * FROM pg_logical_slot_get_changes('test_slot', NULL, NULL, 'include-xids', '0');
   lsn     | xid |                       data
-----------+-----+--------------------------------------------------
 0/16D30F8 | 691 | BEGIN
 0/16D32A0 | 691 | table public.data: INSERT: id[int4]:2 data[text]:'arg'
 0/16D32A0 | 691 | table public.data: INSERT: id[int4]:3 data[text]:'demo'
 0/16D32A0 | 691 | COMMIT
 0/16D32D8 | 692 | BEGIN
 0/16D3398 | 692 | table public.data: DELETE: id[int4]:2
 0/16D3398 | 692 | table public.data: DELETE: id[int4]:3
 0/16D3398 | 692 | COMMIT
(8 rows)

Prev	Up	Next
F.39. tcn	Home	F.41. tsm_system_rows

F.39. tcn

Home

F.41. tsm_system_rows