[PERFORM] does update of column with no relation imply a relation check of other column?

[Anibal David Acosta]

For example:

Table A

-id (PK)

-name

 

Table B

-table_a_id (PK, FK)

-address 

 

When I do an insert on table B, the database check if value for column
"table_a_id" exists in table A

But, if I do an update of column "address" of table B, does the database
check again?

 

My question is due to the nature of and update in postgres, that basically
is a new version "insert".

 

Thanks