Question: What is the index_rs_asc
hint? Also, when do I use the index_rs_asc hint tips
hint in a query with an index hint?
Answer: Oracle has provided an
index hint that directs Oracle to use a specified index.
However, prior to the introduction of index_rs_asc
and index_rs_desc, Oracle did not specify what type
of index access to perform:
1 - Index full scan
2 - Index fast full scan
3 - Index range scan (ascending)
4 - Index range scan (descending)
The index_rs_asc hint is used to invoke an
ascending index range scan upon the target index.
There is also the related index_rs_desc hint to
force an descending index range scan.
Using these hints, you can not only direct that an index
be used, but direct how the index will access the table.
The index_rs_asc hint can accept arguments for the
target table name and the target index name:
select index_rs_asc (emp
emp_id_idx)
stuff
from
emp;
select index_rs_dec (c
cust_state_idx)
stuff
from
customer
c;
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