[GENERAL] nested view with outer joins - best practices

[Bohdan Linda]

Hello,

I have noted one very strange thing which I would like to discuss with
you. I have noted that outer joins on nested views takes heavily longer
than the inner ones. Example:

REATE VIEW ports_view AS
SELECT 
    ports.pid, 
    nodes.nname
FROM 
    ports JOIN nodes ON nodes.nid = ports.pnode;

EXPLAIN ANALYZE
SELECT
*
FROM
    services_subints LEFT JOIN ports_view as prts ON services_subints.port = 
prts.pid


http://explain-analyze.info/query_plans/2078-query-plan-811

but if I rewrote the view as:

SELECT
*
FROM
    (services_subints LEFT JOIN ports as prts ON services_subints.port = 
prts.pid) 
    INNER JOIN nodes AS prn ON prts.pnode = prn.nid

http://explain-analyze.info/query_plans/2079-query-plan-812

if I revert to original nested view and use inner join I get similar plan as 
above.

Here is my question:

1) What are the best practices, if I want to use nested views?
2) Will my plan get better with new version of pgsql ( currently its 8.0.x )

Thank you,
Bohdan 

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