Query Processing and Optimization
Query Processing and Optimization
Query Processing and Optimization
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• Statistics<br />
Operation 3: σ followed by a π<br />
• Relation statistics: r Customer = 200 b Customer = 10<br />
• Attribute statistics:s Street = 10<br />
• Result relation size: 10 tuples.<br />
• Operation: Linear search of Customer. Leave result in<br />
main memory (one block).<br />
• Cost: C 3 = 10<br />
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