In APEX dictionary view APEX_APPLICATION_PAGE_IR_RPT is column REPORT_VIEW_MODE. This column has value REPORT or GROUP_BY in APEX 4.1.1.00.23 when Interactive Report (IR) GROUP BY mode exists. If user change IR mode between REPORT and GROUP BY mode also value of APEX_APPLICATION_PAGE_IR_RPT.REPORT_VIEW_MODE change.
In APEX 4.2 (on apex.oracle.com) seems that column APEX_APPLICATION_PAGE_IR_RPT.REPORT_VIEW_MODE has no meaning and it is always null.
Is this intentionally or this is some kind of bug?
Is there any other way to query information if IR is in GROUP BY mode?
I checked user preferences and APEX_APPLICATION_PAGE_IR_GRPBY dictionary view but it seems they don't change when user switch IR between REPORT or GROUP_BY mode.