Re: Extending SQL in C using VARIABLE length type

Carsten Kropf <ckropf2(at)fh-hof(dot)de> writes:
> Thanks a lot so far. I adopted my structures and am now storing two fields (v_len_ and dimensions) and the storage is now working properly. If I now would try to combine two of these points to a range (like cube) including an upper and a lower bound n-dimensional point structure, I don't get the point how to achieve this.

Well, you can either make that a separate data type with its own
specialized functions for extracting the points, or you can make it into
an array, or possibly a composite type (record). The example code seems
to be headed towards the first of these but maybe you should consider
the alternatives.

The main problem with your example code seems to be that it's confusing
a struct with a pointer to a struct. If you made the struct members
be "struct PointND" rather than pointer to same, it would probably
work, as long as points aren't actually variable-length. Otherwise
you'd need to deal with the fact that "lower" isn't really at a fixed
offset in the larger struct.

regards, tom lane