Example to Unveil the Power of Oracle Cost-Based SQL Optimizer

A user who has a SQL statement takes a long time to execute, actually the SQL is not very complicated, but it has a very complex execution plan.

Mimic SQL text ：
SELECT TO_CHAR(SYSDATE, 'yyyy-mm-dd') AS STAT_DATE,
SYSDATE AS STAT_TIME,
X.TABLE_NAME,
NVL(X.NUM_ROWS, 0) AS TABLE_ROWS,
NVL(ROUND(X.NUM_ROWS * X.AVG_ROW_LEN / 1024, 2), 0) AS TABLE_SIZES,
Y.CREATED AS CREATE_TIME,
Z.COMMENTS AS TABLE_COMMENT,
H .COL_CNT
FROM ALL_TABLES X,...

Example to Unveil the Power of Oracle Cost-Based SQL Optimizer