Subject Re: [Firebird-Architect] Index structures
Author Arno Brinkman
Hi Jim,

> >At Fulda, I was approached by Nickolay Samofatov and Arno
> >Brinkmann on the subject of numeric indexes. They did
> >some performance measurements that suggest three things.
> >
> >
> >First the engine spends an inordinate amount of time in
> >btr.c/compress.
> >
> >Second, the engine spends measurably less time in that
> >routine if there's a hot floating point box on the machine.
> >
> >Thoughts?
> This seems a little implausible to me. Before any conclusions are drawn,
> I'd like to see the data.

I have done a query on a table with 1 million rows which joins another table
with 1 million rows. Pagesize = 8192, PK's are INTEGER, buffers = 10000,
Win2K, FB1.5-SS. The join criteria contains a equal comparision so that for
every record on table1 a index-lookup is done on table2 (which returns 1
record, PLAN JOIN(T1 NATURAL, T2 INDEX (PK_TABLE2)) ). These are the results
of Quantify :

Arno Brinkman