CSCE 4523 DBMS – Midterm Study Guide

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CSCE 4523 DBMS – Midterm Study Guide – covers Chapters 1-3, 5, 8-12
Open book, open notes, emphasis is on understanding the material, grading is on a curve
DBMS Architecture - Chapters 1-3
 Three layer architecture (physical, logical = conceptual, application) – mappings between the layers –
logical and physical independence properties (encapsulation boundaries)
 How DBMS relates to logic, information retrieval (e.g., google)
 Closed world assumption
Data Models – Chapter 3
 What is a data model?
 Relational model
 Primary key, candidate key, foreign key
 Entity Integrity – Referential Integrity
 Give example of integrity constraint and integrity constraint violation
Relational Algebra – Chapter 5
 Why is it called an algebra? Relational closure
 Project, select, join (theta, outer, natural), union, intersection
 Aggregation operators like Sum, Average
 Views
 Triggers 1
Relational Calculus – SQL – Chapter 3, 5
 Why is it called a calculus?
 Data definition language - Create/Alter/Drop {catalog, schema, table, view, domain}
 Data manipulation language - Insert/Update/Delete
 Query language - Select .. from .. where .. group by .. having .. order by ..
 Joining a table with itself e.g. courses and their prerequisites
 Nested queries: selects, joins, … inside of selects
 Null values – meaning of nulls and truth table
 Views – what they are – materialized views – can you update views (what problem do you run into)
Interfacing a programming language to a DBMS – ODBC – Chapter 8, esp. 8.5
Physical Data Organization – Chapter 9
 Records
 Disk organization, sectors, seek-rotational latency-block transfer
 Virtual memory
 Access paths – Primary index, secondary index
 Heap, Hash, Tree index – relative access cost
 Clustered//Unclustered and Sparse/Dense indexes 1
 Multiple attributes, Multi-level index 1
 Static/Dynamic indexes
 B-tree, B+-tree
 Extendable hashing, linear hashing 1
 Join indexes 1
 Logical and physical pointers
 Grid-based storage (in class, not in the book)
Query Processing, Optimization and Tuning – Chapter 9.8, 10, 11, 12
 Query tree, query execution plan
 Identities, Join-order
 Main steps in optimization, Heuristic vs. cost-based optimization
 Join alternatives – nested loop join, sort-merge join, hash join
 External sorting
 Tuning – design decisions, monitoring, 80-20 rule
SURLY – SURLY Spec
 Representation of tuples, tables, indexes
 Methods an index must handle
 Tradeoffs re Heap, Hash, and Tree index
1
Not covered in class or on test, but read about this – worth knowing.
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