# Optimizer Hint
+ `Hint` The syntax of
  + Behavior commented by /*+... */ follows SELECT, UPDATE, or DELETE
  + Hint is case insensitive
  + Multiple different hints need to be separated by commas
```
SELECT /*+ USE_INDEX(t1, idx1, idx2) */ * FROM t1;
SELECT /*+ IGNORE_INDEX(t1, idx1, idx2) */ * FROM t t1;
SELECT /*+ HASH_JOIN(t1, t2) */ * FROM t1，t2 WHERE t1.id = t2.id;
SELECT /*+ USE_INDEX(t1, idx1), HASH_AGG(), HASH_JOIN(t1) */ count(*) FROM t t1, t t2 WHERE t1.a = t2.b;
```
------------------------------------------------------------
Syntax for hint
- Comments by /*+... */ follow SELECT, UPDATE, or DELETE
- Hint is case insensitive
Multiple different hints need to be separated by commas
```
SELECT /*+ USE_INDEX(t1, idx1, idx2) */ * FROM t1;
SELECT /*+ IGNORE_INDEX(t1, idx1, idx2) */ * FROM t t1;
SELECT /*+ HASH_JOIN(t1, t2) */ * FROM t1，t2 WHERE t1.id = t2.id;
SELECT /*+ USE_INDEX(t1, idx1), HASH_AGG(), HASH_JOIN(t1) */ count(*) FROM t t1, t t2 WHERE t1.a = t2.b;
```