Transitioning from Shapefiles to Geodatabases

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Transitioning from Shapefiles to Geodatabases
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Topics

• Intros
• Review GDB Concepts/Formats
• Tips and Tricks/Lessons Learned
• Hands-on Converting SHP to GDB

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Why use GDBs?

• Improve data integrity, consistency, speed
• Faciliate data management (editing, multi-user,
  etc.)
• Handy storage container
• Expanded functionality
• Subtypes, domains, relationship classes
• Topology rules
• Enforce spatial references
• Networks, Terrains
• But, GDBs are not appropriate for all
  situations!!!

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GDB Pitfalls

• Complexity complicates utilization
• Map display of related features, identification
  of attributes
• Querying across relationships often requires SQL
  statements
• Data delivery challenges
• Creation and maintenance requires good GIS skills
• Relationship Classes ltgt Database Integrity
  Constraints

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SHP Pitfalls
Does

• Flat-file format
• Restrictive naming convention
• Lacks topology
• Hard to track updates/versions
• No inherent mechanisms to enforce
• data integrity
• Multiple conversions required when
• dealing with GPS and other data sources

(Analogy courtesy of Joel Cusick AKRO!)
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GDB Options at 9.2
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(No Transcript)
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Geodatabase
Feature Dataset
Feature Classes
Relationship Classes
Object Tables
In a feature class, a row stores a feature
(sort of similar to a row in a DBF of a shapefile)
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Subtypes

• Allow categorization of features
• for display
• for analysis
• for validation
• Defined at feature class level

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Relationship Classes

• Associate feature classes to object tables or
• object tables to object tables
• assign behaviors (e.g. cascades)
• assign rules (a type of integrity)
• Not materialized as database relationships!!!

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Domains

• Data validation and integrity
• Defined at geodatabase level
• Useable across all FCs, tables

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3 GDB Raster Data Types
Raster Datasets
Raster Catalogs
Raster Attributes in feature classes or tables
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Raster Attribute Tables

• Anyone remember .VAT (value attribute tables)
  in Arc/INFO?

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Topology Rules

• Manage how feature classes share geometries
  (nodes/points, arcs/lines, polys)
• Enforce geometric relationships and consistencies
• Enhance editing, data validation (visually)
• Examples of rules (currently there are 25)
• Line must not self-intersect
• Line must not have dangles
• Polygons must not have overlaps

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Other Features of 9.2 GBDs

• Annotation feature classes
• Networks/Routing
• Terrains
• Versioning, Replication and Archiving
• Cartographic Representations
• High Precision Coordinates

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Resources

• ArcGIS Help (surprisingly useful)
• http//webhelp.esri.com
• EGIS ESRI UC 2007 site
• http//egis.nps.gov/services/esriuc2007.aspx
• ESRI Virtual Campus
• http//data2.itc.nps.gov/gis/esri/vc.cfm
• Tools/Utilities (Geodatabase Designer, XML
  Export, Case Tools, ArcToolbox)

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Converting to GDBs

• What are your goals?
• How will your data be used?
• Who are your users?
• Who maintains the data?
• Storage vs. Usage
• Read-only vs. Active Editing
• Sophisticated GDB capabilities do you really
  need them?

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Tips and Tricks
Lessons Learned
Aneth Wight and Russ DenBleyker (NCPN, CANY,
COLM) - Vegetation Geodatabases Heather Stanton
(GRE) - Data models, topology and personal
SDE Judy Daniels and Branon Barrett (SRI) - File
geodatabases and imagery Peter Lindstrom (CAVE)
- Park data management and workflows
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Soil Resource Inventory and Geodatabases

• Judy Daniels
• Project/Data Manager
• 303.969.2091

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SRI File Geodatabase

• Limitless storage capability
• No Lock Files!
• Increased performance
• for large files
• Raster Catalog
• Imagery Management
• no need to cache images referenced by the file
  GDB
• Store individual images (SRI does not use
  mosaics)
• Do not use the add data function in ArcMap
  drag image catalog object from ArcCatalog to
  ArcMap TOC (prevents loading of overlapping
  images)
• Note Raster datasets are continuous single
  raster

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SRI Personal GDB

• Locking issue with MSAccess
• In ArcGIS (desktop and server), MDB file will
  lock if opened by someone with read/write
  permission (i.e. the author)
• No lock files produced with multiple users who
  have read-only access
• Therefore, problems occur with mixed user
  permissions and are a concern when distributing
  data

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Using Help Files Stored on a Server

• On Window Server 2003 OS
• SRI uses help files to share soil characteristics
• When complied as HTML, Windows sees it as a
  security risk
• Open in HTML help window blocked as security
  risk
• LOL - both are MS products!!!
• When complied as individual HTML pages, not a
  security risk
• Open with a Internet Explorer window
• Problem resolved!!!

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Data Modeling and Design

• Choose a practical level of detail/normalization
• Start with a schema (exported as XML or designed
  in ArcCatalog)
• Or, just hack away at it (exports/imports in
  ArcCatalog, use interchange files)

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Data Prep Some Tips

• BACKUPS!!!!!
• Geometry Issues
• Run Repair and Clean (example tool/script)
• Data clean-up (duplicates, etc.)
• Skeleton of GDB model match up data
• Data interchange (temp tables, XML, etc.)
• Test structure and logic understand initial
  pitfalls of your data
• Script everything you can easy do overs