1. Identify the source of the PostgreSQL 42723 error:

SELECT * FROM pg_stat_activity WHERE state = '42723'

2. Check the PostgreSQL log file for more information about the error:

tail -f /var/log/postgresql/postgresql-.log

3. Check the PostgreSQL configuration file for any misconfigurations:

cat /etc/postgresql//main/postgresql.conf

4. Check the PostgreSQL system catalogs for any inconsistencies:

SELECT * FROM pg_catalog.pg_class

5. Check the PostgreSQL system tables for any inconsistencies:

SELECT * FROM pg_catalog.pg_tables

6. Check the PostgreSQL system views for any inconsistencies:

SELECT * FROM pg_catalog.pg_views

7. Check the PostgreSQL system functions for any inconsistencies:

SELECT * FROM pg_catalog.pg_proc;

8. Check the PostgreSQL system triggers for any inconsistencies:

SELECT * FROM pg_catalog.pg_trigger;

9. Check the PostgreSQL system roles for any inconsistencies:

SELECT * FROM pg_catalog.pg_roles

10. Check the PostgreSQL system indexes for any inconsistencies:

SELECT * FROM pg_catalog.pg_indexes

11. Check the PostgreSQL system constraints for any inconsistencies:

SELECT * FROM pg_catalog.pg_constraints

12. Check the PostgreSQL system sequences for any inconsistencies:

SELECT * FROM pg_catalog.pg_sequences

13. Check the PostgreSQL system statistics for any inconsistencies:

SELECT * FROM pg_catalog.pg_statistic

14. Check the PostgreSQL system locks for any inconsistencies:

SELECT * FROM pg_catalog.pg_locks;

15. Check the PostgreSQL system settings for any inconsistencies:

SELECT * FROM pg_catalog.pg_settings

16. Check the PostgreSQL system extensions for any inconsistencies:

SELECT * FROM pg_catalog.pg_extension

17. Check the PostgreSQL system user mappings for any inconsistencies:

SELECT * FROM pg_catalog.pg_user_mappings

18. Check the PostgreSQL system foreign data wrappers for any inconsistencies:

SELECT * FROM pg_catalog.pg_foreign_data_wrappers

19. Check the PostgreSQL system foreign servers for any inconsistencies:

SELECT * FROM pg_catalog.pg_foreign_servers

20. Check the PostgreSQL system foreign tables for any inconsistencies:

SELECT * FROM pg_catalog.pg_foreign_tables

21. Check the PostgreSQL system large objects for any inconsistencies:

SELECT * FROM pg_catalog.pg_largeobject

22. Check the PostgreSQL system languages for any inconsistencies:

SELECT * FROM pg_catalog.pg_language

23. Check the PostgreSQL system casts for any inconsistencies:

SELECT * FROM pg_catalog.pg_cast

24. Check the PostgreSQL system operators for any inconsistencies:

SELECT * FROM pg_catalog.pg_operator

25. Check the PostgreSQL system operator classes for any inconsistencies:

SELECT * FROM pg_catalog.pg_opclass

26. Check the PostgreSQL system operator families for any inconsistencies:

SELECT * FROM pg_catalog.pg_opfamily

27. Check the PostgreSQL system collations for any inconsistencies:

SELECT * FROM pg_catalog.pg_collation

28. Check the PostgreSQL system conversions for any inconsistencies:

SELECT * FROM pg_catalog.pg_conversion

29. Check the PostgreSQL system access methods for any inconsistencies:

SELECT * FROM pg_catalog.pg_am

30. Check the PostgreSQL system tablespaces for any inconsistencies:

SELECT * FROM pg_catalog.pg_tablespace

31. Check the PostgreSQL system resource queues for any inconsistencies:

SELECT * FROM pg_catalog.pg_resqueue

32. Check the PostgreSQL system resource groups for any inconsistencies:

SELECT * FROM pg_catalog.pg_resgroup

33. Check the PostgreSQL system event triggers for any inconsistencies:

SELECT * FROM pg_catalog.pg_event_trigger

34. Check the PostgreSQL system policies for any inconsistencies:

SELECT * FROM pg_catalog.pg_policy

35. Check the PostgreSQL system replication slots for any inconsistencies:

SELECT * FROM pg_catalog.pg_replication_slots

36. Check the PostgreSQL system publications for any inconsistencies:

SELECT * FROM pg_catalog.pg_publication

37. Check the PostgreSQL system subscriptions for any inconsistencies:

SELECT * FROM pg_catalog.pg_subscription

38. Check the PostgreSQL system statistics views for any inconsistencies:

SELECT * FROM pg_catalog.pg_stat_all_tables

39. Check the PostgreSQL system statistics functions for any inconsistencies:

SELECT * FROM pg_catalog.pg_stat_functions

40. Check the PostgreSQL system statistics views for any inconsistencies:

SELECT * FROM pg_catalog.pg_stat_user_tables

41. Check the PostgreSQL system statistics views for any inconsistencies:

SELECT * FROM pg_catalog.pg_stat_user_indexes

42. Check the PostgreSQL system statistics views for any inconsistencies:

SELECT * FROM pg_catalog.pg_stat_user_functions

43. Check the PostgreSQL system statistics views for any inconsistencies:

SELECT * FROM pg_catalog.pg_stat_activity

44. Check the PostgreSQL system statistics views for any inconsistencies:

SELECT * FROM pg_catalog.pg_stat_replication

45. Check the PostgreSQL system statistics views for any inconsistencies:

SELECT * FROM pg_catalog.pg_stat_database

46. Check the PostgreSQL system statistics views for any inconsistencies:

SELECT * FROM pg_catalog.pg_stat_bgwriter

47. Check the PostgreSQL system statistics views for any inconsistencies:

SELECT * FROM pg_catalog.pg_stat_ssl

48. Check the PostgreSQL system statistics views for any inconsistencies:

SELECT * FROM pg_catalog.pg_stat_xact_all_tables

49. Check the PostgreSQL system statistics views for any inconsistencies:

SELECT * FROM pg_catalog.pg_stat_xact_user_tables

50. Check the PostgreSQL system statistics views for any inconsistencies:

SELECT * FROM pg_catalog.pg_stat_xact_user_functions

51. Check the PostgreSQL system statistics views for any inconsistencies:

SELECT * FROM pg_catalog.pg_stat_xact_user_indexes

52. Check the PostgreSQL system statistics views for any inconsistencies:

SELECT * FROM pg_catalog.pg_statio_all_tables

53. Check the PostgreSQL system statistics views for any inconsistencies:

SELECT * FROM pg_catalog.pg_statio_user_tables

54. Check the PostgreSQL system statistics views for any inconsistencies:

SELECT * FROM pg_catalog.pg_statio_user_indexes

55. Check the PostgreSQL system statistics views for any inconsistencies:

SELECT * FROM pg_catalog