Hi all
recently I have given one interview and some questions were asked where I got puzzled.. please help
1)If a table has duplicate data and we wan to select distinct data,what are the factors we keep in mind or when will we use distinct or group by ??is there any difference in explain plan of both.
2)Is hash range partition is possible ?? or any other composite partitioning is possible where primary partition is hash ?? if no why is it so
3)what kind of algorithm is implemented in index searching in b -tree
4) when to use global indexes and when local
i have tried to find answers of these questions on google also but not finding answers ...please help