Subject Re: [Firebird-Architect] Extending execution path information in Vulcan
Author Jim Starkey
Arno Brinkman wrote:
> Hi,
> I like to get some more information from the engine about the execution path choosen.
> The information were i'm talking about, are the estimation numbers calculated by the optimizer such as Cardinality, Selectivity, Cost.
> Recently i added an information item (isc_info_sql_get_raw_plan) to get the the raw (isc_info_xxx items) data from the execution path on the client, because the PLAN text information doesn't show all information.
> Now is my proposal to extend these information items with isc_info_rsb_estimation and under this item the items for cardinality, selectivity and cost.
> If nobody has objects i'll add this functionality to Vulcan.
> The next question is how to represent a double (which data structure) in those information items.
Do you actually need the precision of a double? A simpler alternative
is to use a number with an implicit denominator, e.g. 200 meaning 200 /
10000. If 10,000 isn't fine enough, pick a different implicit denominator.


Jim Starkey
Netfrastructure, Inc.
978 526-1376