pg_logicalinspect The pg_logicalinspect module provides SQL functions that allow you to inspect the contents of logical decoding components. It allows the inspection of serialized logical snapshots of a running PostgreSQL database cluster, which is useful for debugging or educational purposes. By default, use of these functions is restricted to superusers and members of the pg_read_server_files role. Access may be granted by superusers to others using GRANT. pg_get_logical_snapshot_meta(filename text) returns record Gets logical snapshot metadata about a snapshot file that is located in the server's pg_logical/snapshots directory. The filename argument represents the snapshot file name. For example: postgres=# SELECT * FROM pg_ls_logicalsnapdir(); -[ RECORD 1 ]+----------------------- name | 0-40796E18.snap size | 152 modification | 2024-08-14 16:36:32+00 postgres=# SELECT * FROM pg_get_logical_snapshot_meta('0-40796E18.snap'); -[ RECORD 1 ]-------- magic | 1369563137 checksum | 1028045905 version | 6 postgres=# SELECT ss.name, meta.* FROM pg_ls_logicalsnapdir() AS ss, pg_get_logical_snapshot_meta(ss.name) AS meta; -[ RECORD 1 ]------------- name | 0-40796E18.snap magic | 1369563137 checksum | 1028045905 version | 6 If filename does not match a snapshot file, the function raises an error. pg_get_logical_snapshot_info(filename text) returns record Gets logical snapshot information about a snapshot file that is located in the server's pg_logical/snapshots directory. The filename argument represents the snapshot file name. For example: postgres=# SELECT * FROM pg_ls_logicalsnapdir(); -[ RECORD 1 ]+----------------------- name | 0-40796E18.snap size | 152 modification | 2024-08-14 16:36:32+00 postgres=# SELECT * FROM pg_get_logical_snapshot_info('0-40796E18.snap'); -[ RECORD 1 ]------------+----------- state | consistent xmin | 751 xmax | 751 start_decoding_at | 0/40796AF8 two_phase_at | 0/40796AF8 initial_xmin_horizon | 0 building_full_snapshot | f in_slot_creation | f last_serialized_snapshot | 0/0 next_phase_at | 0 committed_count | 0 committed_xip | catchange_count | 2 catchange_xip | {751,752} postgres=# SELECT ss.name, info.* FROM pg_ls_logicalsnapdir() AS ss, pg_get_logical_snapshot_info(ss.name) AS info; -[ RECORD 1 ]------------+---------------- name | 0-40796E18.snap state | consistent xmin | 751 xmax | 751 start_decoding_at | 0/40796AF8 two_phase_at | 0/40796AF8 initial_xmin_horizon | 0 building_full_snapshot | f in_slot_creation | f last_serialized_snapshot | 0/0 next_phase_at | 0 committed_count | 0 committed_xip | catchange_count | 2 catchange_xip | {751,752} If filename does not match a snapshot file, the function raises an error. Bertrand Drouvot bertranddrouvot.pg@gmail.com