How to find unindexed foreign key with Oracle
How to find unindexed foreign key with Oracle
All credits to : this post. Here is the script :
SELECT table_name, constraint_name,
cname1
|| NVL2 (cname2, ',' || cname2, NULL)
|| NVL2 (cname3, ',' || cname3, NULL)
|| NVL2 (cname4, ',' || cname4, NULL)
|| NVL2 (cname5, ',' || cname5, NULL)
|| NVL2 (cname6, ',' || cname6, NULL)
|| NVL2 (cname7, ',' || cname7, NULL)
|| NVL2 (cname8, ',' || cname8, NULL) COLUMNS
FROM (SELECT b.table_name, b.constraint_name,
MAX (DECODE (POSITION, 1, column_name, NULL)) cname1,
MAX (DECODE (POSITION, 2, column_name, NULL)) cname2,
MAX (DECODE (POSITION, 3, column_name, NULL)) cname3,
MAX (DECODE (POSITION, 4, column_name, NULL)) cname4,
MAX (DECODE (POSITION, 5, column_name, NULL)) cname5,
MAX (DECODE (POSITION, 6, column_name, NULL)) cname6,
MAX (DECODE (POSITION, 7, column_name, NULL)) cname7,
MAX (DECODE (POSITION, 8, column_name, NULL)) cname8,
COUNT (*) col_cnt
FROM (SELECT SUBSTR (table_name, 1, 30) table_name,
SUBSTR (constraint_name, 1, 30) constraint_name,
SUBSTR (column_name, 1, 30) column_name, POSITION
FROM user_cons_columns) a,
user_constraints b
WHERE a.constraint_name = b.constraint_name
AND b.constraint_type = 'R'
GROUP BY b.table_name, b.constraint_name) cons
WHERE col_cnt >
ALL (SELECT COUNT (*)
FROM user_ind_columns i
WHERE i.table_name = cons.table_name
AND i.column_name IN
(cname1,
cname2,
cname3,
cname4,
cname5,
cname6,
cname7,
cname8
)
AND i.column_position <= cons.col_cnt
GROUP BY i.index_name)
/
Just a quick addition : all foreign key don’t have to be indexed but many do.