Two possibilities, though neither seems likely.
a) gv$sql_plan_monitor (and gv$sql_monitor) may be one of those (rare)
views that DOESN'T run cross-instance, so if the query is running on
instance but the session you're using to look at the monitor report is
connect to another instance you wouldn't see it.
b) there is another hidden parameter that limits the number of plans that
can be monitored at any one time. This is _sqlmon_max_plan, default 80, and
is the number of plans PER CPU. Maybe something has jammed the counter of
v$sql_monitor at the maximum so your query can't be captured.
Regards
Jonathan Lewis
On Fri, 7 May 2021 at 17:50, Henry Poras <henry.poras@xxxxxxxxx> wrote:
I think I'm missing something silly here, but I don't know what.
I'm having an issue with getting a sql_monitor report and I'm running
(well, ran) out of ideas on what to try next. I have a long running query
(~2 hours on 12.1.0.2) for which I am trying to get a report using
dbms_sqltune.report_sql_monitor. The result returned is always empty. So I
tried:
- setting _sqlmon_max_planlines to 1000 (execution plan is ~600 lines
using display_cursor('adaptive'))
- checked statistics_level which is correct. It is TYPICAL
- control_management_pack_access is DIAGNOSTIC+TUNING (also correct)
I thought it might be aging out of memory since it ran long, but running
the report and looking in gv$sql_monitor after 2, and 10-15 minutes still
showed nothing. Adding a MONITOR hint to the CTE and body of the sql didn't
help. Neither did running an ALTER SYSTEM SET EVENTS 'sql_monitor [sql:...]
force=true'.
I can't figure out why I am getting nothing. Anybody have any ideas?
Thanks.
Henry
