exec dbms_system.set_bool_param_in_session(, , ‘_rowsource_execution_statistics’, true)

For others (not you!) that don’t know, that parameter, controlled by statistics_level, is the one that precisely turns on the row level stats shown in the plan.

Poeple have been wishing for years to have a procedure like set_string_param_in_session in dbms_system. Dream has not come true!

Great article!

You have a typo in gather table stats. t2_vc was gathered twice; the first one should be for t1_vc. Also, after you create index t1_vc_i2 on t1_vc (n2,n1), why do you re-gather stats for table t1_vc? Index stats is automatically created (unless you turn off _optimizer_compute_index_stats), table stats stay the same anyway.