sql - Oracle EXPLAIN PLAN FOR 不返回任何内容

Question

我在 Oracle 数据库上运行以下查询:

EXPLAIN PLAN FOR
SELECT *
FROM table_name

但是，它没有返回任何数据。当我删除 EXPLAIN PLAN FOR 子句时，查询确实按预期运行。感谢您的帮助!

如果相关，我将通过 Teradata 和 Jupyter IPython 笔记本访问数据库。

Answer 1

来自 Using EXPLAIN PLAN :

The PLAN_TABLE is automatically created as a global temporary table to hold the output of an EXPLAIN PLAN statement for all users. PLAN_TABLE is the default sample output table into which the EXPLAIN PLAN statement inserts rows describing execution plans

EXPLAIN PLAN FOR  SELECT last_name FROM employees;

This explains the plan into the PLAN_TABLE table. You can then select the execution plan from PLAN_TABLE.

Displaying PLAN_TABLE Output

• UTLXPLS.SQL
• UTLXPLP.SQL
• DBMS_XPLAN.DISPLAY table function

我建议使用:

EXPLAIN PLAN FOR SELECT * FROM table_name;

SELECT * FROM TABLE(dbms_xplan.display);