MySQL [test]> EXPLAIN SELECT /*+ HASH_AGG() / count() FROM t1;
±---------------------------±----------±----------±---------------------------------------±----------------------------------+
| id | estRows | task | access object | operator info |
±---------------------------±----------±----------±---------------------------------------±----------------------------------+
| StreamAgg_28 | 1.00 | root | | funcs:count(Column#34)->Column#23 |
| └─IndexReader_29 | 1.00 | root | | index:StreamAgg_8 |
| └─StreamAgg_8 | 1.00 | cop[tikv] | | funcs:count(1)->Column#34 |
| └─IndexFullScan_25 | 127077.00 | cop[tikv] | table:t1, index:account_i0(account_no) | keep order:false |
±---------------------------±----------±----------±---------------------------------------±----------------------------------+
hint为啥没有生效呢？