The MicroStation Undo command has no record of spatial queries in Bentley Map. For this reason, there is a built-in warning dialog that displays when you perform a spatial query that reads:
Selecting the “Don’t’ show this message again” option suppresses the dialog from displaying for future queries. Pressing OK will initiate the query process while Cancel will halt the process. Once the query has been started, the Cancel button on the Query dialog can be used to halt the process.
To prohibit the dialog from displaying altogether, set GDI_SUPPRESS_QUERY_NON_UNDOABLE_WARNING = 1 for Oracle or GDI_SUPPRESS_SQL_SERVER_QUERY_NON_UNDOABLE_WARNING = 1 for SQL Server. These variables can be defined in the macro node in the Geospatial Administrator.