[thelist] Nested SQL question

apatrick at oracular.com apatrick at oracular.com
Tue Sep 12 15:02:06 CDT 2000

|> that happens anyway, under the database covers -- views and even
|> subqueries are first translated into joins -- so if you can write them as
|> joins, it may aid comprehension, and sometimes you can influence the
|> actual execution strategy chosen by the optimizer...

|> You seem to be mentioning a lot of things that are in:

|> Use Oracle's Explain Plan to Tune Your Queries
|> http://evolt.org/index.cfm?menu=8&cid=2986

|> In fact, I think adam even wrote this one. I wish the title was more general
|> so that non-Oraclonians would read it... it's a really good article.

Why yes, I did write that article.  ;-)  

I gave it an Oracle title because it's fairly Oracle-centric but you're right; there 
are some good tuning tips for anybody in there.  The reason why using 
explain-plan (in any database) is a good idea is so that you can learn things like 
what rudy mentioned by looking at explain plans.  You could put together a query 
like yours and the look at the plan and find out the database is translating it into 
a join in this manner or that manner and then tweak it to make it scream.

So next time should I use the title "Use explain plan to tune your queries" and 
then specify in the body that I'll approach it from an Oracle angle? 

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