Transitioning from Shapefiles to Geodatabases

1. Transitioning from Shapefiles to Geodatabases

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

3. 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!!!

4. 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 <> Database Integrity Constraints

5. 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!)

6. GDB Options at 9.2

8. 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)

9. Subtypes • Allow categorization of features: • for display • for analysis • for validation • Defined at feature class level

10. 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!!!

11. Domains • Data validation and integrity • Defined at geodatabase level: • Useable across all FCs, tables

12. 3 GDB Raster Data Types Raster Datasets Raster Catalogs Raster Attributes in feature classes or tables

13. Raster Attribute Tables • Anyone remember *.VAT (value attribute tables) in Arc/INFO?

14. 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”

15. Other Features of 9.2 GBDs • Annotation feature classes • Networks/Routing • Terrains • Versioning, Replication and Archiving • Cartographic Representations • High Precision Coordinates

16. 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)

17. 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?

18. 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

19. Soil Resource Inventory and Geodatabases Judy Daniels Project/Data Manager 303.969.2091

20. 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

21. 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

22. 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!!!

23. 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)

24. 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’