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GeoDB, ESRI Geodatabase ArcSDE

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Format Description Properties Explanation of format description terms

Identification and description Explanation of format description terms

Full name ESRI Geodatabase ArcSDE
Description

A GeoDB_SDE geodatabase is a multi-user ArcGIS geodatabase implemented on an RDBMS platform. The GeoDB, ESRI Geodatabase ArcSDE or GeoDB_SDE is a subtype of the GeoDB. The GeoDB is the primary data storage model for ArcGIS. It is a container of spatial and attribute data and enables the user to store many different types of GIS data within its structure. Its structure is implemented either in an RDBMS or as a collection of files in a file system. GeoDB_SDE is implemented on the customer's choice of supported RDBMS platforms that include IBM DB2, IBM Informix, Oracle, PostgreSQL, and SQL Server. Multi-user geodatabases leverage the underlying RDBMS architecture to provide better data security, such as access permission control for individual datasets, distributed file management, backup/recovery capabilities, and data integrity.

There are three types of multi-user geodatabases: enterprise, workgroup, and desktop. The storage capacity and number of possible concurrent users vary with each type.

  • Enterprise Geodatabases -- Intended for large-scale enterprise application scenarios, it can be scaled to any size and can support any number of users, running on computers of any size and configuration. It is the most robust of all the geodatabase types. It is designed to be easily integrated into an enterprise IT structure so GIS data can be shared across the entire enterprise system.
  • Workgroup Geodatabases -- Intended for the small- to medium-sized departmental application scenarios. Geodatabase and RDBMS management, such as defining users and their data access permissions, is performed entirely within the ArcGIS suite of software. A workgroup geodatabase has a maximum size limit of 4 gigabytes and supports up to 10 simultaneous users, all of which could be editors. I
  • Desktop Geodatabase -- This is designed for small teams or a single user who requires the functionality of a multiuser geodatabase. It has a maximum size limit of 4 gigabytes, and uses the ArcGIS Desktop suite of software for setup and management. The difference between a workgroup geodatabase and a desktop geodatabase is that the desktop geodatabase only supports up to three concurrent users (one editor and two viewers). I
Production phase Single user geodatabases (such as personal and file geodatabases) can be migrated to multi-user geodatabases using migration tools included in the ArcGIS software suite. See Migrating your existing data into the Geodatabase.
Relationship to other formats
    Affinity to ArcInfo Coverage , ESRI ArcInfo Coverage . The ArcGIS Coverage format is a legacy format superseded by the ESRI Arc Geodatabase data model that is expressed in single and multi-user geodatabases. Coverages cannot be edited in ArcGIS 8.3 and subsequent versions.
    Subtype of GeoDB, ESRI Arc Geodatabase. The data model that serves as the framework for all Arc geodatabases, whether single user or multi-user. This data model has superseded the ESRI ArcInfo Coverage format which cannot be edited in ArcGIS 8.3 and subsequent versions.
    Affinity to GeoDB_File, GeoDB, ESRI Geodatabase (File-based). This geodatabase option, implemented as a collection of binary files in a file system, is one option for data storage for a single-user ESRI Geodatabase.
    Affinity to GeoDB_Personal, GeoDB, ESRI Geodatabase (Personal). An option for data storage for a single-user ESRI Geodatabase that is implemented as a single Microsoft Access file. ESRI recommends file geodatabases over Microsoft Access Personal Geodatabases, because they offer more functionality and better performance. The Personal Geodatabase format is not described at this time on this website.
    Affinity to GeoDB_XML, ESRI Geodatabase (XML). Used by ArcGIS to import and export all items and data in a geodatabase such as domains, rules, feature datasets, and topologies.

Local use Explanation of format description terms

LC experience or existing holdings  
LC preference  

Sustainability factors Explanation of format description terms

Disclosure A proprietary database structure used in ESRI GIS products.
    Documentation ESRI does not provide a complete specification of the database structure employed in ArcGIS. The different types of geodatabases are described in Types of geodatabases, ArcGIS 9.2 Desktop Help, January 14, 2008.
Adoption The geodatabase data model was introduced by ESRI in the late 1990s with the release of version ArcGIS 8.0. The release of the ArcGIS suite constituted a major change in ESRI's software offerings, aligning all their client and server products under one software architecture known as ArcGIS, developed using Microsoft Windows COM standards. While the ESRI shapefile is still quite prevalent in the industry, at least for sharing and transferring datasets among different systems, the geodatabase is becoming the mechanism of choice for data sharing and data interoperability among organizations, and departments within a single organization. While older ESRI (non-ArcGIS) products are still available, most of the GIS software market share that ESRI holds (approximately 36 percent worldwide as of 2002) is taken by ArcGIS products. See ArcGIS from Wikipedia and COTS GIS: The Value of a Commercial Geographic Information System for more information.
    Licensing and patents ESRI Licensing agreements detail the terms of use and compliance for ESRI GIS software per http://www.esri.com/legal/software-license.
Transparency TBD
Self-documentation TBD
External dependencies

Software dependencies:

  • Personal ArcSDE -- Beginning wtih Version 9.2 of the ArcGIS suite, ArcEditor and ArcInfo include the Microsoft SQL Server Express database to allow personal ArcSDE geodatabases fro three simultaneous users, one of whom can edit data. SQL Server Express is limited to run on one CPU or Core within a Socket and use 1 GB RAM. Maximum database size is 4 GB.
  • Workgroup ArcSDE -- ArcGIS Server for Workgroups includes ArcSDE support for SQL Server Express. This level of ArcSDE allows up to 10 simultaneous Windows desktop users and editors plus any number of additional server connections from applications, as governed by license agreement. SQL Server Express is limited to running on one CPU or Core with a maximult of 1 GB RAM and database size limit of 4 GB.
  • Enterprise ArcSDE -- Enterprise ArcSDE is included with ArcGIS Server for Enterprises. This is the traditional ArcSDE technolgy that runs on Oracle, SQL Server, PostgreSQL, IBM DB2, and IBM Informix. The Enterprise ArcSDE can scale to databases of any size and number of users, running on computers of any size and configuration.
Technical protection considerations TBD

Quality and functionality factors Explanation of format description terms

GIS images and datasets
Normal functionality

The multi-user geodatabase, like the single user geodatabase can store tables, feature classes, feature datasets, and functionality such as rules, relationships, and geometric networks. Advanced feature types are supported such as geometric and logical networks, true curves, complex polylines, and user-defined features. ArcSDE technology provides additional geodatabase functionality that is not available in single-user geodatabases. This includes:

  • Versioning -- With versioning, a multiuser geodatabase can manage and maintain multiple states while preserving integrity in the database. A version represents an alternative, independent, persistent view of the geodatabase; supports multiple concurrent editors; and does not involve data duplication. Versioning is the default editing environment in a multiuser geodatabase. It explicitly records states of individual features and objects as they are modified, added, and/or retired. It is the framework that enables multiple users to access and edit the same data simultaneously and provides support for long transactions (i.e., database changes that span long periods of time). Simple queries are used to view and work with any desired state for a particular point in time or see an individual user's current edits. This capability allows a GIS user to create versions of a geodatase for the stages of a project, reconcile differences between versions, and update the master version of a geodatabase. See Understanding versioning for more information about this topic.
  • Geodatabase Replication -- This is a data distribution method provided through the ArcGIS system. With geodatabase replication, GIS data can be distributed across two or more geodatabases in a manner that allows them to synchronize any data changes that are made. This functionality is built on top of the versioning environment and supports the full geodatabase data model, including geospatial relationships, such as topologies and geometric networks. Three types of replication workflows are available: two-way, one-way, and checkout/check-in replication. In this asynchronous model, the replication is loosely coupled; this means that each replicated geodatabase can work independently and still synchronize changes with one another. Since geodatabase replication functionality is implemented at the ArcGIS software level, the RDBMS platforms involved can be different. For example, a user could replicate data from a multiuser geodatabase implemented on Oracle to a multiuser geodatabase implemented on SQL Server. Geodatabase replication can be used in connected and disconnected environments. It works with local geodatabase connections over a network, as well as over the Internet, using geodata services available in ArcGIS Server.
  • Geodatabase Archiving -- When enabled on a dataset, geodatabase archiving captures any and all changes made to the dataset in the default version of the multiuser geodatabase. The edits are recorded in an archive class, which is a duplicate copy of the original dataset. The archive class contains additional fields that record a feature's edit history in the geodatabase. This functionality can be used with historical versions in the geodatabase. A historical version provides a read-only view of the geodatabase at a specific moment in time. See Geodatabase archiving for more information.
  • Long and Short Transaction Management -- The ArcSDE geodatabase includes advanced support for situations when added users and the requirement to manage data from an array of sensor networks, for example, makes the need for transaction management more critical. In GIS, besides the more common, short database transactions (spanning seconds or minutes) that are orchestrated on the DBMS's short transaction framework, long transactions that span long periods of time (hours, even days and months) may be needed. In addition, a single editing session in a GIS can involve changes to multiple rows in multiple tables that may need to be undone and redones. Users may want to treat each edit session as a single transaction when they commit their changes in a system that is disconnected from the central, shared database. During these specialized GIS data flow processes, the GIS database must remain continuously available for daily operations, where each user might have a personal view or state of the shared GIS database. ArcSDE plays a key role during these operations by managing the high-level, complex GIS transactions on the simple DBMS transaction framework. ArcSDE does this by storing change information as delta records in the database; isolating multiple edit sessions using versions; and supporting complex transactions, automatic archive, and historical queries. See An overview of editing and maintaining data for more information.

Other functionality associated with ArcSDE geodatabases include the capability to define topological and associative relationships and rules that determine how feature classes interact. Relationships are associations between two objects in a feature dataset, either nonspatial objects or spatial features. By defining relationships, referential integrity is ensured in the geodatabase. Four broad types of validation rules for maintaining database integrity are supported including validation rules, network connectivity rules, relationship rules, and custom rules. See Working with the Geodatabase: Powerful Multiuser Editing and Sophisticated Data Integrity for more information about how to use rules and relationships, and how to facilitate multi-user editing in ArcSDE geodatabases.

Support for GIS metadata There are no special provisions for containing GIS metadata in the GeoDB_SDE format.

File type signifiers and format identifiers Explanation of format description terms


Notes Explanation of format description terms

General  
History Prior to ArcGIS 9.2, ArcSDE was a stand-alone software product. At the ArcGIS 9.2 release, ArcSDE was integrated into both ArcGIS Desktop and ArcGIS Server.

Format specifications Explanation of format description terms


Useful references

URLs


Last Updated: Monday, 27-Feb-2017 09:55:29 EST