Covered Query - response (2) by rajeev saravanan

Hi Dieter ,

Thanks for the quick turnaround

I would like to extent my understanding with a simple scenario

Now for example i have a set of 5 columns which are frequently queried and a particular query utilises only these 5
if i were to define a compound SI using these 5 then the next time i use any of these 5 columns in either select or in the where clause
then the optimizer would make a choice to read the subtable instead of accessing the larger base table

however if the query uses only say 2-3 columns then it may not choose to use the subtable

Also in case of SI is there a necessity that all the index columns be used in the where clause of the query

looking for your inputs !

Any documetation would be helpful