How to verify if two tables have exactly the same data?

Question

Basically, we have one table (original table) and it is backed up into another table (backup table); thus the two tables have exactly the same sche

Answer 1

select count(*) 
from lemmas as original_table 
      full join backup_table using (lemma_id)
where backup_table.lemma_id is null
      or original_table.lemma_id is null
      or original_table.lemma != backup_table.lemma

The full join / check for null should cover additions or deletions as well as changes.

• backup.id is null = addition
• original.id is null = deletion
• neither null = change