Re: Query execution for intervals

> > Oracle is the RDBMS. I am using standard index (create index....)
> create index can create several kinds of indices.
In what way should I create the indexes to make the best possible search?

> > The meaning of linear is if the response time of the query execution
> > can be calculated by the formula: time = k * n, where n is the total
> > number of records.
> Even if the DBMS only use one index, the time is not linear.

If my original assumtion is correct, the response time would be linear. The query engine has to traverse all events with the start value lower than the given time. In average 50% percent of the events has to be traversed. The time could be calculated as: time = 0.5 * k * n, where n is the total number of events.

One possible solution would be that the query engine might use the knowledge of the time value compared to the existing start and end values, and the average percent ratio might be significant lower than 50%. But it would still be a linear response time.

> Have you done an experiment to collect some data about the actual response
> time for running the query ?

No, I was hoping to get a qualified answer at this forum.

Best regards,
Fredrik Received on Thu Feb 09 2006 - 06:44:46 CST