What does PLAN_HASH_VALUE equal 0 means? If the plans just has a hash value of 0, then look like it's not normal for tons of sql having plan hash value as 0. The purpose of hash function is to distribute the values evenly after hash, but in this case, most of the sql has hash value of 0
SYS@TEST:prod SQL> select * from (select c.PLAN_HASH_VALUE,count(*) cnt from v$sqlstats c group by c.PLAN_HASH_VALUE order by cnt desc) where rownum<=10;
PLAN_HASH_VALUE CNT
--------------- ----------
0 10951
1546270724 434
2693950485 334
2137506556 330
3857681095 317
2675117847 314
353669763 313
3633231507 186
836014615 171
2032550489 170
10 rows selected.