Interval referential integrity

Hello all,

I’m developing a specialist application that needs a different kind of
referential integrity! I need interval referential integrity where the
bounds of the referenced interval must overlaps (or be equal) the bounds of
the referencing interval!

For example,

----------------------------------------------------------------------------
---------------------------------------------------------------

-- I did the functions IN and OUT to get this working

Create type t_interval (

Lower int,

Upper int

);

CREATE TABLE tableA (

tableA_id integer,

name varchar(30),

boundA t_interval,

constraint pk_tableA primary key (tableA, boundA)

);

CREATE TABLE tableB (

tableB_id integer,

boundB t_interval,

constraint fk_B_A foreign key (tableB_id, boundB) references tableA

);

----------------------------------------------------------------------------
---------------------------------------------------------------

So, tableA.boundA OVERLAPS tableB.boundB!

Example,

Insert into tableA values (1, ‘test 1’, ‘(1, 5)’);

Insert into tableB values (1, ‘(2, 4)’); --> POSSIBLE

Insert into tableB values (1, ‘(1, 3)’); --> POSSIBLE

Insert into tableB values (1, ‘(3, 7)’); --> NOT POSSIBLE

I know that I need to change some (may be a lot of) things in the source
code. Specifically in the RI_TRIGGER.C (isn´t???). But I need some help to
do this!

Anyone have an idea?

Thanks in advance!