Hi,

I am trying to tune one of my sql statements and i am not sure whether i should use an hint in the sql statement or just let it do a full table scan. Any help would be appreciated. This partcular table holds 86022 rows and the avg_row_length is 41.


By using a rule hint the optimizer is doing an index range scan and then it is accessing the table by index rowid.

By Using first_rows hint the cost is 75 and it is doing an index range scan and then it is accessing the table by index rowid.
The cardinality for this statement is 638 and bytes value is 26158.

Without using any hint the cost is 40 and it is doing a full table scan. The cardinality and the cost is same as using the first_rows.


In which scenarios should we avoid using rule hint.

Thans in advance.