instead of the more conventional xxxx_id or just id?
sorry if this may be a foolish question to some, but i'm trying to think thru
a junior colleagues's proposal. the discussion occurred while we were
discussing naming our foreign key constraints using the convention
"childtable_parenttable_colname_fk".
Are you talking about the constraint name or the name of the column holding the data?
Identifiers in PostgreSQL can only be 64 characters (bytes?) long.
If it is the column name I wouldn't get too crazy or people writing out SQL joins manually will be asking you to pay their medical bills...
I generally avoid naming any column "id" - tables get short code aliases and those prefix the "id". I then name the column in the FK the exact same name. I rely on system defaults for choosing the names of the corresponding constraints and indexes.