ArcSDE is ESRI's technology for accessing and managing geospatial data within relational databases. ArcSDE technology supports reading and writing of multiple standards, including (among other data storage options) OGC for simple features, the ISO standard for spatial types, and the Oracle Spatial format. At ArcGIS 9.2, ArcSDE technology is enhanced to support nonversioned editing and full SQL access to geodatabases managed within Oracle DBMSs.
ArcSDE is unique in its support of the following capabilities:
- It is open and interoperable across multiple DBMSs (Oracle, SQL Server, DB2, and Informix).
- It is standards-based, using as its native data structure the OGC binary simple features standard and the ISO spatial type (for Oracle, IBM DB2, and IBM Informix only).
- It supports full, open SQL access to geodatabases stored in Oracle, IBM DB2, and IBM Informix.
- It fully supports the Oracle format for feature storage (using Oracle Spatial and Oracle Locator).
- It provides high performance and scales to a large number of users. ArcSDE geodatabases outperform all other solutions for storage and retrieval of spatial data.
When do you need ArcSDE?
When you need a multiuser geodatabase that can be edited and used simultaneously by many users, the ArcSDE geodatabase provides the solution. It adds the ability to manage both a shared, multiuser geodatabase and a number of critical version-based GIS workflows. The ability to leverage an organization's enterprise relational databases is a key advantage of the ArcSDE geodatabase.
ArcSDE also supports users who need to manage long transactions and versioned-based workflows; for example, to manage historical archives, distributed editing, federated replicas managed across many DBMS architectures, and to support multiuser editing scenarios.
ArcSDE geodatabases work with a variety of DBMS storage models (IBM DB2, IBM Informix, Oracle, and Microsoft SQL Server). ArcSDE geodatabases are used in a wide range of work groups, departments, and enterprise settings. They take full advantage of their underlying DBMS architecture to support:
- Extremely large, continuous GIS databases
- Many simultaneous users
- Long transactions and versioned workflows
- Relational database support for GIS data management (providing the benefits of a relational database such as scalability, reliability, security, backup, and integrity).
- Standards-based SQL Types for Spatial when the DBMS supports this capability.
Through many large geodatabase implementations, it has been found that DBMSs are efficient at moving the type of large binary objects reqeuired for GIS data in and out of tables. In addition, GIS database sizes and the number of supported users can be much larger when using ArcSDE.
How is ArcSDE technology included in ArcGIS?
In the past, ArcSDE was sold as a separate ESRI product. At ArcGIS 9.2, ArcSDE technology is still included in ArcGIS; however, it is no longer a separate product. Instead, ArcSDE technology has been integrated into both the ArcGIS Server and ArcGIS Desktop products.
ArcSDE geodatabases readily scale from personal, single-user geodatabases, through workgroup geodatabases, up to extremely large enterprise geodatabases.
There are three levels for accessing and using ArcSDE technology in ArcGIS. Geodatabase capabilities are available in the following ESRI software:
Personal ArcSDE technology included with ArcEditor and ArcInfo
Beginning at ArcGIS 9.2, ArcEditor and ArcInfo include the Microsoft SQL Server Express database free of charge. These software products also include ArcSDE capabilities to support personal ArcSDE geodatabases for three simultaneous users—one of whom can edit data.
SQL Server Express is limited to only use 1 CPU (or Core within a Socket) and utilize 1GB RAM. The maximum database size for SQL Server Express is 4GB.
Within ArcEditor and ArcInfo, the ArcCatalog application provides the ability to fully administer and manage ArcSDE geodatabases using SQL Server Express. This provides full ArcSDE geodatabase capabilities for a few users and one editor at a time. You set up and manage these ArcSDE geodatabases within ArcCatalog. No extra software or database administration expertise is required.
Workgroup ArcSDE technology included with ArcGIS Server Workgroup
ArcGIS Server Workgroup includes ArcSDE support for SQL Server Express. With this level of ArcSDE, you can use SQL Server Express for up to 10 simultaneous Windows desktop users and editors (for example, users of ArcView, ArcEditor, ArcInfo, a custom ArcGIS Engine application, AutoCAD, MicroStation, and so on) plus any number of additional server connections that can be supported by your configuration.
SQL Server Express is limited to only use 1 CPU (or Core) and utilize 1GB RAM. Maximum database size is 4GB.
As with Personal ArcSDE, you can use ArcEditor or ArcInfo to create, administer, and manage workgroup ArcSDE geodatabases. You set up and manage these Workgroup ArcSDE geodatabases using SQL Server Express within ArcCatalog. No extra database administration expertise is required.
In this context, you can think of ArcGIS Server Workgroup as an extension for ArcEditor or ArcInfo to help you manage and serve Workgroup ArcSDE geodatabases. Of course, ArcGIS Server can perform many more functions and tasks.
Enterprise ArcSDE technology included with ArcGIS Server Enterprise
This is the traditional ArcSDE technology that runs on Oracle, SQL Server, IBM DB2, and IBM Informix and can scale to databases of any size and number of users, running on computers of any size and configuration. Users provide their own DBMS license for this level of ArcSDE use. The DBMS is typically administered and managed by a database administrator (DBA).
The following table further compares the types of ArcSDE geodatabases:
||SQL Server Express geodatabases
||Enterprise DBMS geodatabases
||SQL Server Express
||Any of the Workgroup, Standard, Developer, or Enterprise editions of SQL Server, Oracle, DB2, or Informix
|Type of client to database connection
||Direct connect or ArcSDE application server (ArcSDE service)
|Maximum total data size
||Limited only by operating system and DBMS used
||ArcSDE Administration Commands; some tasks possible in DBMS administration software and in ArcCatalog
||Licensed per CPU or core
||Dependent on DBMS
|User able to alter configuration
|Type of user/group logins
||Operating system (Windows) authenticated
||DBMS or operating system authenticated
||Uses same code page as the server
||Customizable; options dependent on DBMS
|XML column support
|Versioned editing support