The issue - Missing index on foreign key
What is all about When you create a foreign key, you should always create an index on it (and NO, postgres do not create automaticly an index for you). Should You Always Index Foreign Keys in PostgreSQL? Foreign keys are an essential part of relational database design. They ensure referential integrity by linking rows between tables. But when it comes to performance, many developers wonder: “Should I always add an index to a foreign key column?” ...