Re: Ignore histograms on sql level

   2 - filter("CUST_YEAR_OF_BIRTH"=1913)

SELECT /*+ FULL(c)
* opt_param('_optimizer_use_histograms','false')* */

    COUNT(*)
FROM sh.customers c
WHERE cust_year_of_birth = 1913;

|   0 | SELECT STATEMENT   |           |      1 |        |
|   1 |  SORT AGGREGATE    |           |      1 |      1 |
|*  2 |   TABLE ACCESS FULL| CUSTOMERS |      1 |    *740* |
----------------------------------------------------------

   2 - filter("CUST_YEAR_OF_BIRTH"=1913)

Of course the ideal way would be to drill down into why does Oracle end up with cardinality misestimation - or let some of the Oracle's adaptive features "help you out" - but from our past chats I figure that it's the adaptive features that are actually involved in the problems you've been seeing? :-)

An alternative option could be to have two sets of stats, the published stats and pending stats (with different histograms or settings). And the problem session/SQL (that needs to see alternative stats), would have to set *optimizer_use_pending_statistics* = true at session level or with opt_param hint. But it's somewhat hacky - and I vaguely recall an issue in past where my query wasn't actually using pending stats despite the parameter setting (don't remember exact details, maybe I did something wrong)