| Subject | Re: How to determine the selectivity of a composite index? |
|---|---|
| Author | karolbieniaszewski |
| Post date | 2011-05-28T07:26:24Z |
--- In firebird-support@yahoogroups.com, "sergiogarciaruso" <sergiogarciaruso@...> wrote:
SELECT r.RDB$INDEX_NAME, r.RDB$FIELD_NAME, r.RDB$FIELD_POSITION, r.RDB$STATISTICS
FROM RDB$INDEX_SEGMENTS r
Karol Bieniaszewski
>look at this system table
> Hi, I know how to determine the selectivity of an index associated with a single field (http://www.firebirdfaq.org/faq167/), but I would like to know how to do it with multiple fields (composite index). It's that possible?
>
> Best regards,
> Sergio
>
SELECT r.RDB$INDEX_NAME, r.RDB$FIELD_NAME, r.RDB$FIELD_POSITION, r.RDB$STATISTICS
FROM RDB$INDEX_SEGMENTS r
Karol Bieniaszewski