I would genarete more test data and compare my first version with the new version.
-----Original Message----- From: Rafal Kedziorski [mailto:[EMAIL PROTECTED] Sent: Friday, February 21, 2003 3:30 PM To: [EMAIL PROTECTED] Subject: [SQL] good style?
hi,
I have 8 tables and this query:
select u.users_id, m.name as mandant_name, u.login_name, u.password, u.first_name, u.last_name, u.creation_date, g.name as groups_name, ae.acl_entry_id, a.name as acl_name, p.name as permission_name
from mandant m, users_2_groups u2g, groups g, users u, permission p, acl a, acl_entry ae, groups_2_acl_entry g2ae
where m.mandant_id = u.mandant_id and
u2g.groups_id = g.groups_id and
u2g.users_id = u.users_id and
g2ae.groups_id = g.groups_id and
g2ae.acl_entry_id = ae.acl_entry_id and
ae.acl_id = a.acl_id and
ae.permission_id = p.permission_id
I'm not using JOIN for get this information. would be JOIN a better sql programming style? faster?
As there is no outer join syntax to use in WHERE, you need to write LEFT JOINs anyway. And in this case it looks better if you write all joins as JOIN clauses.
When using JOIN you are directing Postgres to use exactly this join order. I found it preferrable over letting query optimizer to decide. Generally you know better what tables will contain more rows and what less. It's more important in development phase, because there is usually not much test data and all tables look the same to optimizer.
Rafal
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