Survey
* Your assessment is very important for improving the work of artificial intelligence, which forms the content of this project
Download Database System Concepts - Chapter 13: Query
Document related concepts
Transcript
Join Algorithms Database System Concepts Several different algorithms to implement joins Overview Query Cost The Selection Operation Sorting Tuples The Join Operation Nested-Loop Join Block Nested-Loop Join Indexed Nested-Loop Join Merge-Join Hash Join Complex Joins Other Operations Evaluating Expressions Nested-loop join Block nested-loop join Indexed nested-loop join Merge-join Hash-join The choice is based on cost estimates The next examples use the following information: Number of records of customer : 10 000 depositor : 5 000 Number of blocks of customer : 400 depositor : 100
