How to improve the performance of SQL query in Oracle DB - sql

Question

one of the tab is broken in the Application (when hit that tab it keeps on rotating and calling the particular service and getting 404 error after sometime). we created indexes for few columns in Application DB to see if that improves performance. Creating indexes didn't make much difference.
so We planned to rewrite the sql query to improve the performance and fix it.
select distinct
editedUser.*
from
users editedUser,
relationship_ref editedUserRelationship,
users approvingUser,
user_role approvingUserRoles,
role_permission approvingUserRolePermissions,
account approvingUserAccount
where
approvingUser.user_id = 175263
and approvingUser.user_id = approvingUserRoles.user_id
and approvingUserRoles.role_id = approvingUserRolePermissions.role_id
and approvingUserRoles.user_role_status_id = 2
and editedUserRelationship.relationship_id =
editedUser.submitted_relationship_id
and (approvingUser.account_id = approvingUserAccount.account_id
or approvingUser.account_id is null)
and editedUser.review_status = 'R'
and approvingUserRolePermissions.permission_id =
editedUserRelationship.view_pending_permission_id;
It is taking nearly 6 mins.So can one please suggest how to use the proper joins in this query. It has 36 columns and 30,000 records.

Answer 1

Rearranged in a style that is easier to read (to me at least), I get this:
select distinct ed.*
from users ap
join user_role ro
on ro.user_id = ap.user_id
join account ac
on ac.account_id = ap.account_id or ap.account_id is null
join role_permission rp
on rp.role_id = ro.role_id
join relationship_ref re
on re.view_pending_permission_id = rp.permission_id
join users ed
on ed.submitted_relationship_id = re.relationship_id
where au.user_id = 175263
and ro.user_role_status_id = 2
and ed.review_status = 'R'
How many approving users have null account_id? For any of those, you retrieve all accounts in the system. Is that actually the business requirement? I'm not sure that it makes any sense. The query does not make any further use of that table, so perhaps you can remove the account join entirely.