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 Slow amalgamation of tables

Author  Topic 

rmg1
Constraint Violating Yak Guru

256 Posts

Posted - 2010-10-18 : 05:35:13
Hi all

I've got a fairly complex set of select queries using temporary tables which run quite quickly.
When I'm trying to put all the tables together using left joins (one of the tables contains a set of "master" data), everything grinds to a halt.

Do left joins slow everything down or is it just a case of the number of tables I'm using (20) that is taking the time?

Sachin.Nand

2937 Posts

Posted - 2010-10-18 : 06:32:19
Yes left join pulls all the records from the left table along with the matching records to the right table.
Post your query along with the table schema & sample records.Maybe it is an issue with missing indexes.

PBUH

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visakh16
Very Important crosS Applying yaK Herder

52326 Posts

Posted - 2010-10-19 : 13:19:32
the question do you really need so much left join. Probably worth posting some sample data from the table and explaining what you want.

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SQL Server MVP
http://visakhm.blogspot.com/

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