Re: Sequencial scan in a JOIN

On 06/05/2012 08:31 AM, Andrew Jaimes wrote:

> the default_statistics_target is set to 200, and I have run the analyze
> and reindex on these tables before writing the email.

Out of idle curiosity, how do these two variants treat you?

SELECT count(1)
FROM e_usersessions s
JOIN l_userqueue q ON (q.userid = s.entityid)
JOIN a_activity a ON (a.activequeueid = q.queueid)
WHERE s.sessionkeepalivedatetime > 20120605082131943
AND a.vstatus = 1
AND a.ventrydate > 0
AND a.sbuid = s.sbuid
AND a.assignedtoid = 0
AND a.status <> '0'

SELECT count(1)
FROM e_usersessions s
JOIN l_userqueue q ON (q.userid = s.entityid)
WHERE s.sessionkeepalivedatetime > 20120605082131943
AND EXISTS (
SELECT 1 FROM a_activity a
WHERE a.activequeueid = q.queueid
AND a.sbuid = s.sbuid
AND a.vstatus = 1
AND a.ventrydate > 0
AND a.assignedtoid = 0
AND a.status <> '0'
)

--
Shaun Thomas
OptionsHouse | 141 W. Jackson Blvd. | Suite 500 | Chicago IL, 60604
312-444-8534
sthomas(at)optionshouse(dot)com

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