Using the GEQO

Hi,

 

I have a few queries on the use of the geqo.

 

1. Since the value of geqo_threshold is12, does the geqo get automatically activated for queries with 12 or more joins?

2. Can the geqo threshold be set to a smaller value like 4 or 5?

3. How do we come to know whether the geqo has been used to solve the query or not? Does Explain Analyze report it?

4. If we change the value of geqo_threshold do we have to change any other parameters necessarily?

 

Please let me know these basics on the use of the geqo.

 

Thanks

Regards

Swati