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Alien

how to optimize queries in general?

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I\'m curious how people optimize their select statements if they are complex. MySQL 4.0 doesn\'t support nested queries(4.1 supports, but it is an alpha version), so many complex queries have to be broken down with some iterations in php scripts.

 

At the beginning I wrote a nested query and thought that it worked, after I ran it...I remembered that it was not a PostgreSQL DB....so I broke down the query into 3 queries with 2 loops.

 

However, the tables are too big(one has 200,000 rows, another has 20,000 rows, the last one has 6,000 rows), so the process takes about 2 hrs to complete on a LAN.

 

I just want to know, in general, how can I optimize select statements?

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yea...indexing will help...but for each insert/delete, I have to pay for it since the index tree changes everytime I insert/delete. I am not sure whether it is worth...I will check with my database schema. Thanks.

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Alien, no problem, and glad I could be of assistance to you.

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