Re: [PERFORM] Performance trouble finding records through related records

[Andy Colson]

On 3/3/2011 3:19 AM, sverhagen wrote:

Andy Colson wrote:

For your query, I think a join would be the best bet, can we see its
explain analyze?



Here is a few variations:


SELECT events_events.* FROM events_events WHERE transactionid IN (
        SELECT transactionid FROM events_eventdetails customerDetails
        WHERE customerDetails.keyname='customer_id'
        AND substring(customerDetails.value,0,32)='1957'
        AND transactionid IS NOT NULL
) ORDER BY id LIMIT 50;

-- http://explain.depesz.com/s/Pnb


explain analyze SELECT events_events.* FROM events_events,
events_eventdetails customerDetails
        WHERE events_events.transactionid = customerDetails.transactionid
        AND customerDetails.keyname='customer_id'
        AND substring(customerDetails.value,0,32)='1957'
        AND customerDetails.transactionid IS NOT NULL
ORDER BY id LIMIT 50;

-- http://explain.depesz.com/s/rDh


explain analyze SELECT events_events.* FROM events_events
JOIN events_eventdetails customerDetails
        ON events_events.transactionid = customerDetails.transactionid
        AND customerDetails.keyname='customer_id'
        AND substring(customerDetails.value,0,32)='1957'
        AND customerDetails.transactionid IS NOT NULL
ORDER BY id LIMIT 50;

-- http://explain.depesz.com/s/6aB


Thanks for your efforts!


Huh.  Pretty much exactly the same.  I'm sorry but I think I'm at my 
limit.  I'm not sure why the nested loop takes so long, or how to get it 
to use something different.

-Andy

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