Subject Re: [firebird-support] Re: Compound Index
Author Arno Brinkman
Hi Ivan,

> In older FB versions, the clause WHERE COLUMN1 > 100 caused that
> even rows with COLUMN1=100 were internally fetched (and discarded).
> Now with FB2 I made a test, and the statistics looks like the index
> is read for values COLUMN1 >= 100, but only rows with COLUMN1 > 100
> are fetched, is it possible ? (The difference of fetches for these two conditions
> seems equal to the number of index pages required for indexing value 100)

> Anyway, ">" now performs much faster thanks to not fetching "=" values.
> Was this improved/fixed in FB2 ? I do not remember
> to see any note in Release notes ...

Indeed this is improved by Vlad in FB2. We still need to scan the index-entries (thus read index-pages), but are
ignoring the base (100 in this case).

Regards,
Arno Brinkman
ABVisie

-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-
General database developer support:
http://www.databasedevelopmentforum.com

Firebird open source database (based on IB-OE) with many SQL-99 features:
http://www.firebirdsql.org
http://www.firebirdsql.info

Support list for Interbase and Firebird users:
firebird-support@yahoogroups.com

Nederlandse firebird nieuwsgroep:
news://newsgroups.firebirdsql.info