You want to capture column grou

单项选择题 You want to capture column group usage and gather extended statistics for better cardinality estimates for the CUSTOMERS table in the SH schema. Examine the following steps: 1. Issue the SELECT DBMS_STATS.CREATE_EXTENDED_STATS (‘SH’, ‘CUSTOMERS’) FROM dual statement. 2. Execute the DBMS_STATS.SEED_COL_USAGE (null, ‘SH’, 500) procedure. 3. Execute the required queries on the CUSTOMERS table. 4. Issue the SELECT DBMS_STATS.REPORT_COL_USAGE (‘SH’, ‘CUSTOMERS’) FROM dual statement. Identify the correct sequence of steps.（）: A、3，2，1，4; B、2，3，4，1; C、4，1，3，2; D、3，2，4，1

热门试题