Subject Re: how do i speed this up?
Author Svein Erling Tysvær
I don't know whats wrong with your understanding (I don't understand
the calculation of key length), but
agrees with Firebird. Try a length of 64 or less...


--- In, "martinknappe" wrote:
> Hi Adam, hi Set,
> thanx for your replies. Creating a joint index on asterm, id sounds
> very much like a plan. I just tried to do that with:
> And this is what I get:
> key size exceeeds implementation restriction for index
> I thought this may have to do with the fact that I am using
> unicode_fss code point ordering on a field that may contain up to 80
> characters and that the combined index of asterm, id may be too
> big..
> given the fact that creating an index on asterm alone works fine, i
> thought the extra 4 bytes from field id seem to be what makes this
> combined index too big; so what i did was simply reduce the size of
> field asterm from 80 characters to 70 characters (thereby reducing
> the potential index size by 30) and try again - > and i'm still
> getting this error!
> how come it's fine to create an index on an 80-bytes varchar field
> alone, but not, to create a combined one on a 70-bytes varchar field
> and a 4-byte integer? what am i doing wrong here?
> thanx very much,
> martin
> ps: i'm using firebird 1.5