Step 5: Cross Check Stats

Bad estimates can lead to bad plans. Check the table and column stats:

SELECT table_name, last_analyzed, num_rows, owner
FROM dba_tables
WHERE table_name = '<target-table>';

Also check for histograms:

SELECT column_name, histogram, num_distinct, owner
FROM dba_tab_col_statistics
WHERE table_name = '<target-table>';

If LAST_ANALYZED is old or there are no histograms on skewed columns, you may want to gather fresh stats.