ArcGIS Geodatabase Miles Logsdon Spatial Information Technologies, UW Garry Trudeau - Doonesbury

At its most basic level, the geodatabase is a container for storing spatial and attribute data and the relationships that exist among them. Geodatabases are created, edited, and managed using the standard menus and tools in ArcCatalog™ and ArcMap™. A database or file structure used primarily to store, query, and manipulate spatial data. Geodatabases store geometry, a spatial reference system, attributes, and behavioral rules for data. Various types of geographic datasets can be collected within a geodatabase, including feature classes, attribute tables, raster datasets, network datasets, topologies, and many others. Geodatabases can be stored in IBM DB2, IBM Informix, Oracle, Microsoft Access, Microsoft SQL Server, and PostgreSQL relational database management systems, or in a system of files, such as a file geodatabase. ArcGIS Geodatabase:

Personal geodatabase for Microsoft Access: A personal geodatabase for Microsoft Access can be read by multiple people at the same time, but edited by only one person at a time. A personal geodatabase for Access has the.mdb file extension (a format used by Microsoft Access) and has a maximum size of 2 gigabytes (GB). Vector data is stored in the database, while raster data is referenced. Personal geodatabases for Access are appropriate for smaller workgroups and for managing small to moderately sized datasets. File geodatabase: The file geodatabase is a new geodatabase type released at ArcGIS 9.2. A file geodatabase, which has the.gdb file extension, stores datasets in a folder of files on your computer. File geodatabases work across operating systems and can store individual datasets up to 1 terabyte (TB) in size. While only one person can edit an individual item in a file geodatabase at a time, multiple people can view and query the data stored in a file geodatabase at the same time. File geodatabases are the recommended native data format for ArcGIS. Multiuser geodatabase: A multiuser geodatabase is typically found in larger organizations where multiple users need to view and edit the GIS database at the same time. Multiuser geodatabases support versions and replication and require ArcSDE technology and a database management system (DBMS) such as Informix, Microsoft SQL Server, or Oracle.

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Feature Dataset is a collection of feature classes with the same spatial reference. Feature Class is a collection of features that share the same geometry type (point, line, or polygon). Nonspatial Table contains attribute data associated with feature classes Stand alone Feature Classes 1 Feature Dataset 5 Feature Classes Feature datasets primarily store feature classes that have topological relationships (connectivity, adjacency, containment).

Types of Geodatabases ERDAS Imagine ESRI Grid JPEG MrSID TIFF Coverages CAD dBase INFO tables Shapefiles

The file geodatabase uses an efficient data structure that is optimized for performance and storage. File geodatabases use about one-third of the feature geometry storage required by shapefiles and personal geodatabases for Access. File geodatabases also allow you to compress vector data to a read-only format to reduce storage requirements even further. File geodatabases have no storage size limit. Individual datasets within a file geodatabase, such as a feature class or table, do have a size limit of 1 terabyte (TB). The file geodatabase offers improved performance. For example, it can easily support individual datasets containing over 300 million features and datasets that can scale beyond 500 GB per file, while maintaining very fast performance. The file geodatabase offers less restrictive editing locks. Locking can be done per table instead of on the entire database. Lastly, the file geodatabase is supported by many platforms, including Windows and UNIX (Solaris and Linux).