add batch remove batch split batch comment selection show hidden batches hide batch highlight batch
db<>fiddle
donate feedback about
By using db<>fiddle, you agree to license everything you submit by Creative Commons CC0.
Help with an interesting Postgres question: Why isn't an Index Only Scan used on a partition accessed via the parent table?.
SELECT 14
ALTER TABLE
ALTER TABLE
empno ename mgr
7839 KING null
SELECT 1
empno ename mgr
7839 KING null
SELECT 1
empno ename mgr mgr_name
7566 JONES 7839 KING
7698 BLAKE 7839 KING
7782 CLARK 7839 KING
SELECT 3
empno ename mgr mgr
7839 KING null
7566 JONES 7839 KING
7698 BLAKE 7839 KING
7782 CLARK 7839 KING
SELECT 4
empno ename mgr mgr
7839 KING null
7566 JONES 7839 KING
7698 BLAKE 7839 KING
7782 CLARK 7839 KING
7499 ALLEN 7698 BLAKE
7521 WARD 7698 BLAKE
7654 MARTIN 7698 BLAKE
7788 SCOTT 7566 JONES
7844 TURNER 7698 BLAKE
7900 JAMES 7698 BLAKE
7902 FORD 7566 JONES
7934 MILLER 7782 CLARK
7369 SMITH 7902 FORD
7876 ADAMS 7788 SCOTT
SELECT 14
QUERY PLAN
CTE Scan on leveln (cost=19.34..21.36 rows=101 width=72)
  CTE leveln
    -> Recursive Union (cost=0.00..19.34 rows=101 width=72)
          -> Seq Scan on emp (cost=0.00..1.14 rows=1 width=72)
                Filter: (mgr IS NULL)
          -> Hash Join (cost=0.33..1.62 rows=10 width=72)
                Hash Cond: (emp_1.mgr = mgr.empno)
                -> Seq Scan on emp emp_1 (cost=0.00..1.14 rows=14 width=40)
                -> Hash (cost=0.20..0.20 rows=10 width=36)
                      -> WorkTable Scan on leveln mgr (cost=0.00..0.20 rows=10 width=36)
EXPLAIN