Cost at Query

[LilianSL]

Colleagues,

Whenever I execute an Explain Plan to analyze performance, I always have doubts about "cost".
For example, a simple query with the only condition using the primary key, access is done by index, but the cost is very high.
Oh when Query is very simple, I mean, use the index, it does a good access, quickly runs the query, but the cost is still high ..
When it arrives at this point I do not know More what I can do to decrease the cost.
Does anyone have any tips for this?

Grata
Liliansl

[adrianoturbo]

It will depend on some factors so that the optimizer choose the best run plan and give satisfactory cost-based result.
follows some factors that can influence the DML operations perfomance:
- data / statistics volume;
- Use of variables bind
- adjustments in the startup parameters.
From 11G has a nice resource called the result cache, using dynamic views that greatly improve perofmance of DML operations, I recommend taking a look at the concept of: Materialized View.