Re: foundations of relational theory? - some references for the truly starving

Centuries ago, Nostradamus foresaw when michael_at_preece.net (Mike Preece) would write:
> It might be worth mentioning at this stage that the amount of data you
> can store in a Pick item will require far less physical disk space
> than on any other (uncompressed) database. There are two reasons for
> this:
> 1) because every field is of variable length - every datum is just as
> long as it needs to be and no more and empty fields occupy no space at
> all (other than single character system delimiters) - and

This all seems to be nonsense.

Relational database systems commonly use the very same techniques such that every datum is only as long as it needs to be, where NULL columns consume as little as 1 bit.

(We added a NULL column to a Big Database Table yesterday, and it didn't lead to _any_ increase in the size of the table. Nor did it require updating any of the tuples.)

There is no theoretical reason for relational databases to consume more than other sorts, and these days, it tends to be also true in practice...

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