'Cartesian products' diaporamas de présentation

CMPT 454

Query Optimization. CMPT 454. Query Optimization. Parsing Queries Relational algebra review Relational algebra equivalencies Estimating relation size Cost based plan selection Join order. Query Optimization.

1.5k views • 132 slides

Sets

497 views • 37 slides

Seepage as a model of counter-terrorism

CMS Winter Meeting December 2011. Seepage as a model of counter-terrorism. Anthony Bonato Ryerson University. Good guys vs bad guys games in graphs. bad. good. Seepage. motivated by the 1973 eruption of the Eldfell volcano in Iceland

400 views • 26 slides

Partial Orderings

Partial Orderings. Aaron Bloomfield CS 202 Rosen, section 7.6. Introduction. An equivalence relation is a relation that is reflexive, symmetric, and transitive A partial ordering (or partial order) is a relation that is reflexive, anti symmetric, and transitive

207 views • 20 slides

Chapter 2

Chapter 2. The Basic Concepts of Set Theory. Chapter 2: The Basic Concepts of Set Theory. 2.1 Symbols and Terminology 2.2 Venn Diagrams and Subsets 2.3 Set Operations 2.4 Surveys and Cardinal Numbers. Section 2-3. Set Operations. p.60. Set Operations.

640 views • 19 slides

Grouping & aggregation of data

Relational Databases. Grouping & aggregation of data. So far we have looked at retrieving data from multiple tables and the different ways to join the relations/tables that are required. Pulling back lists of data may not be useful if there are large quantities of data retrieve

465 views • 18 slides