'Way merge' diaporamas de présentation

CS411 Database Systems

CS411 Database Systems. 10: Query Processing. Query Execution. Outline. Logical/physical operators Cost parameters and sorting One-pass algorithms Nested-loop joins Two-pass algorithms. Query Execution. Query or update. User/ Application. Query compiler.

1.4k views • 116 slides

Learning Objectives

Learning Objectives. Co-sequential processing matching merging K-way merge Overlapping I/O with Processing heap sort. Co-sequential processing. Co-sequential operations are operations applied to problems that involve : union intersection other complex operations

335 views • 23 slides

Sorting

Sorting. What makes it hard? Chapter 7 in DS&AA Chapter 8 in DS&PS. Insertion Sort. Algorithm Conceptually, incremental add element to sorted array or list, starting with an empty array (list). Incremental or batch algorithm. Analysis In best case, input is sorted: time is O(N)

379 views • 20 slides

External Sorting

External Sorting. Problem: Sorting data sets too large to fit into main memory. Assume data are stored on disk drive. To sort, portions of the data must be brought into main memory, processed, and returned to disk. An external sort should minimize disk accesses. Model of External Computation.

364 views • 19 slides

322 views • 18 slides

ICS 321 Fall 2010 Overview of Query Processing

ICS 321 Fall 2010 Overview of Query Processing. Asst. Prof. Lipyeow Lim Information & Computer Science Department University of Hawaii at Manoa. SELECT * FROM Reserves WHERE sid =101. Query. ? Sid=101. Parse Query. A. B. Reserves. Enumerate Plans. fetch. SCAN ( sid =101).

245 views • 16 slides