[MonetDB-users] Does a primary key based on a single column + numeric improve performance in MonetDB?

Hi,

I am designing the schema of our brand new MonetDB database, and I am not sure whether my previous data modeling instincts are still relevant ;-). In particular, I am wondering:

A) Does the definition of primary keys / foreign keys improve MonetDB performance?

B) I need to do joins with a table whose natural key which is the combination of (bigint, varchar(51)). Is it best to:

1) just add these 2 columns to the dependent tables, and join on these 2 columns.

2) create a single varchar column that would be the concatenation of the bigint + varchar(51) and join on this single varchar column

3) Introduce a numeric+sequential surrogate key (presumably generated from a sequence), and join on the surrogate key.

I am especially interested in the performance / acidental complexity tradeoffs in this situation.

Thanks in advance, - Philippe