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Questions about Executing Explain Plan against a query. [message #249144]

Tue, 03 July 2007 08:56

Rustican
Messages: 51
Registered: July 2006

Member

I'm using Oracle SQL Developer and running the Executive Explain Plan against my queries. I was wondering if there was some explanation of what the COST, CARDINALITY, and BYTES were in the explanation.

I'm not sure what is meant by the COST of the query.

I thought the CARDINALITY of a query was the number of rows returned, but it doesn't seem to be the case.

And is the BYTES information the amount of temp table space the query uses in the database when the returned rows are generated?

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