Hi Yuan, We don't have a cqd to force mdam for all scans in a given query. MDAM_SCAN_METHOD has 3 possible value; ON, OFF and MAXIMUM. ON is the default. If cqd is set to MAXIMUM mdam scan on the right side of a nested join is considered. The cqd in all three settings will only influence whether mdam is considered. It still has to win under the cost model to be chosen.
With a Control query shape we can force mdam as you know. I think we can also a control table statement, though I have not done this recently. Since CQS syntax can get quite unwieldy, I am think of creating a JIRA asking that <<+ mdam(col-list)>> type hints be supported to force index access. The problem with a cqd I think is that there could several scans in one query and maybe we don't want mdam for all of them. Thanks Suresh On Fri, Jul 28, 2017 at 2:57 AM, Liu, Yuan (Yuan) <[email protected]> wrote: > Hi Trafodioneers, > > > > Does anyone know that do we have any cqd to force MDAM query plan? Cqd > mdam_scan_method ‘on’ seems not work. > > > > Best regards, > > Yuan > > Email: [email protected] > > Cellphone: (+86) 13671935540 <+86%20136%207193%205540> > > >
