> > the multi-segment indexes are to optimize commonly used queries.
>
>In this case you can consider removing one or two fields from the index and
> see how much selectivity it lose and how much performance would be
> affected.
So, you are saying that having less fields reduces the index
29.01.2019 21:13, 'Leyne, Sean' s...@broadviewsoftware.com [firebird-support]
wrote:
> the multi-segment indexes are to optimize commonly used queries.
In this case you can consider removing one or two fields from the index and
see how
much selectivity it lose and how much performance would
> > All the FB articles/docs/postings that I have seen have said for
> > performance, index depth should be no more than 3.
>
> This is not a hard requirement, 4 levels may be also OK. Are those multi-
> segment indices primary/unique keys or just for lookup purposes?
{Sorry for the delay in
22.01.2019 20:54, Sean Leyne wrote:
>
> In my database I have some indexes with depth = 4 (db page size is
> already 16KB).
> The indexes are multi-segment, with the fields sequenced from least to
> most selective, and gstat reports a very low selectivity for the index
> (less than 0.0001).
