At 10:29 PM 26/01/2004 +1100, you wrote:

> > CHAR(n) CHARACTER SET OCTETS, where n = 8 * the number of tables involved
> > in the set.
> >
> > Not true that you can't pass it around stored procedures. It will remain
> > stable for the duration of your transaction, *inside your
> > transaction*. Just don't use it to update the rdb$db_key of any
> > other table!
> >
> > /hb
>
>8 * the number of tables? not fields?

Yes, tables. When you join tables, the 8-byte rdb$db_keys are concatenated
together. (Really, each rdb$db_key is 16 hex digits, a combination of the
page id and the offset of the record on the page).

>Anyway - what would you use it for?

;-) Read my forthcoming book - it's an optimization topic in chapter 22.
But seriously, Claudio is the one who has done all the research. Read his
articles at www.cvalde.net

/hb