'Relation partitions output' diaporamas de présentation

Parallel Database Primer

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Lecture 13: Query Execution

Lecture 13: Query Execution. Where are we?. File organizations: sorted, hashed, heaps. Indexes: hash index, B+-tree Indexes can be clustered or not. Data can be stored inside the index or not. Hence, when we access a relation, we can either scan or go through an index:

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SQL and Query Execution for Aggregation

SQL and Query Execution for Aggregation. Reserves. Example Instances. Sailors. Boats. Queries With GROUP BY. To generate values for a column based on groups of rows, use aggregate functions in SELECT statements with the GROUP BY clause. The target-list contains

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