GIS Design Aspects and Data Modeling Flashcards
Conceptual Model
describes spatial objects as well as logical and topological relationships between spatial objects and the captured spatial entities
Data Structure Model
expresses the spatial objects of the conceptual model in terms of transfer data structures - based on traditional relational and network models - data structures viewed as spatial data structures are both vector and raster models
Transfer Model
express the logical constructs of the transfer form in terms of implementation-media constructs
File Based Transfer
data is a structured file format
Application Programming Interface (API)
data is accessed and exchanged as needed between software systems
Web Services
data is accessed and exchanged over networks and the internet between software components, using http and other web based protocols
Data Owner
user who creates tables, features classes owns those datasets
User Access
database must verify the user accounts that connect to it
Authentication
database checks the list of users to make sure a user is allowed to make a connection - Operating System (OS) authentication or Database Authentication
Groups
grant users based on their common functions
Public Role
right granted to anyone connected to database
Backup and Recover Database
test backup and recovery plan, ensure backups done on schedule
Database Security
prevent hackers, security models, tasks - authentication, authorization, auditing (making sure the right people have the right access)
Storage and Capacity Planning
disk storage is needed and monitor disk space and watch growth trends
Performance Monitoring
identify bottlenecks, tuning (indexing, queries on speed of return, right monitoring tools, capacity of server hardware
Troubleshooting
quickly ascertain problem and correct it
Other
High Availability and ETL functions - Data extraction, transformation, and loading
Requirements Phase
user needs assessment and workflow loads analysis (baseline and peak traffic)
Design Phase
Infrastructure requirements, network communication capacity, hardware and software procurement, software development and data acquisition must be identified
Construction Phase
system procurement, data acquisition and database design, authorization for application design and development, prototype testing
Implementation Phase
Initial Deployment and operational testing, final system delivery, user training, system maintenance operations
Capacity Planning Tool (CPT)
developed as a framework to promote successful GIS system design and implementation
Enterprise GIS Environment
broad spectrum of technology integration of enterprise technologies connected by local area networks, wide area networks, internet communications
Enterprise Technologies
database servers, storage area networks, windows terminal servers, web servers, map servers, desktop clients
Schema
structure or design of the database or database object (table, view, index, stored procedure, trigger) - defines the tables, fields in each table, relationships between fields - a schema will include information on which fields have domains and what those domains are
Data Dictionary
catalog or table containing information about the datasets stored in a database
Domain
the range of values for a particular metadata element
Attribute Domain
enforces data integrity, identify what values are allowed in a field in a feature class
Coded Value Domain
attribute domain that defines a set of permissible values for an attribute in a geodatabase - it has a code and its equivalent value
Range domain
type of attribute domain that defines the range of permissible values for a numeric attribute
Spatial Domain
allowable range for x,y coordinates and for m,z values
Individual Files
shapefiles, file gdb, personal gdb, tables, spreadsheets, CAD, rasters
Databases
direct connection to relational database management systems and big data databases - manage tables and feature classes in database
Geodatabase
stores GIS in central location for easy access
Cloud
store files in the cloud to be accessible anywhere. Editing can be multi or single user editing
Control of Big Data
visualize multiple different types
Integrate Enterprise
Data stored in big business systems to extend their analytical capabilities
Data rules and relationships
define relationships between datasets and set rules ( domains and subtypes)
Manage Metadata
describes content, quality, origin and other characteristics of data
Secures Data
flexibility and control over how GIS platform is deployed, maintained, secured and used
Versioning
allows multiple editors to edit one database by creating “duplicates” of the base
data - changes are recorded with addition and deletion tables - versions can be created or
deleted - edits are isolated in that version until admin merges changes - edits can be posted to
parent version - DEFAULT is the root version
Database Design
process of producing a detailed data model of a database
Conceptual Schema
determine where relationships and dependency is within the data
Logical Data Model
Arrange data in a logical structure that can be mapped into the storage objects supported by the database management system
Physical database design
physical configuration of the database on the storage media - detailed specification of data elements, data types, indexing options, and other parameters residing in the DBMS data directory - modules, hardware, software
Tables
collection of related data held in structured format within a database, contains fields and rows
Views
result set of a stored query on the data - users can query - virtual table computed dynamically from data when the view is accessed
Sequences
ordered collection of objects in which repetitions are allowed (finite or infinite) number of elements is the length of the sequence
Synonyms
Alias or alternate name for a table, view, sequence or other object
Indexes
data structure that improves the speed of data retrieval operations in a database table - causes more storage space and additional writes - quickly locate data in the database - indexes can be on multiple columns
Snapshot
state of a system at a particular point in time - can be a backup
Procedure
subroutine available to applications that access a relational database system (data validation, access control mechanisms)
Trigger
procedural code automatically executed in response to certain events on a particular table or view in a database
Function (Subroutine)
sequence of program instructions that perform a specific task
Package
built from source with one of the available package management systems
Non-schema objects
users, roles, contexts, directory objects
Equals
Topology is equal
Disjoint
No points are in common
Intersects
Some common interior points
Touches
at least one boundary point in common but no interior points
Contains
Feature 2 is within Feature 1
Covers
Every point of Feature 2 is a point of Feature 1
Covered By
every point of feature 1 is a point of feature 2
Within
feature 1 is within feature 2
Crosses
Feature 1 crosses feature 2 at some point
Overlaps
Both features have no common interior points
Desktop
individual user on a computer, make maps, data analysis, data creation
Server
bring GIS into the hands of everyone in organization, allows access to web GIS, control of GIS data on your own infrastructure, control over how GIS platform is deployed, maintained, secured and used
Hosted (cloud)
ability to discover, use, make, and share maps with any device anywhere, anytime - access other users maps and data - connect more people outside of the organization and share the latest maps, data and ideas
Enterprise GIS
integrated through entire organization so that a large number of users can manage, share, and use spatial data and related information to address a variety of needs, including data creation, modification, visualization, analysis, dissemination
*can use hosted(cloud) and server but if data is not stored in cloud and only accessed, then it’s not an enterprise GIS
System Infrastructure
hardware, software and communication network - required information products and spatial and non-spatial data resources - essential spatial analysis, display, and reporting functions, needed data management resources, anticipated number of end users within the department
Vector
coordinate based data model that represents points, lines, polygons - point represented by a coordinate pair, lines and polygons have an ordered list of vertices - attributes associated with each feature
Raster
defines space as an array of equally sized cells in rows and columns - single or multiple bands - each cell has 1 attribute value - raster coordinates are stored by ordering the matrix
Grid
parallel and perpendicular lines for reference as a map projection or coordinate system
TIN
Triangulated Irregular Network - portions vector data into contiguous, nonoverlapping triangles - create Delaunay triangles
Advantages of TIN
small areas with high precision elevation data - more efficient storage than DEM or contour lines
Disadvantages of TIN
requires very accurate data source and costs are expensive, TIN production and use are very computer intensive
Topological
features need to be connected using specific rules
Hierarchial
database that stores related information in a tree-like structure - records can be traced to parent records to a root record
Network
collection of topologically connected networks elements (edges, junctions, turns) - each element is associated with a collection of network attributes
Object Oriented
data management structure stores data as objects (classes) instead of rows and tables as a relational database
