ArcSDE Compressed Binary storage
ArcSDE Compressed Binary storage
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| Release 9.3 |
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The ArcSDE Compressed Binary storage type is the primary storage type for ArcSDE geodatabases stored in SQL Server and was the default storage type for ArcSDE geodatabases stored in Oracle prior to ArcGIS 9.3. It uses a binary storage mechanism for storing feature geometry.
Beginning with ArcGIS 9.3, the default feature storage type for Oracle was changed from Long Raw to ST_Geometry.
The ArcSDE Compressed Binary storage type can be used to store geometry in ArcSDE geodatabases in Oracle or SQL Server databases. Compressing the geometry offers efficient storage and retrieval of spatial data by reducing the space required to store data by as much as 40 percent.
The client application, after verifying the geometry, compresses and sends it to the server, where it is stored in Compressed Binary format in a feature table, or F table. Compressing the geometry on the client unloads the task from the ArcSDE server and reduces the transmission time to send the geometry.
A compressed binary feature class is made up of three tables: the business table, feature table, and spatial index table.
The business table contains attributes and a spatial column. The spatial column is a key to the feature and spatial index tables.
The relationship between the business table and feature table is managed through the spatial column and the feature ID (FID) column. This key, which is maintained by ArcSDE, is unique.
For further description of feature classes stored in the ArcSDE Compressed Binary format, see Feature classes in a geodatabase in SQL Server and Feature classes in a geodatabase in Oracle.
In SQL Server databases, ArcSDE Compressed Binary is the default geometry storage, and it is stored as an image data type.
The DBTUNE table parameter GEOMETRY_STORAGE defines the geometry storage format of a feature class. In geodatabases in SQL Server, the GEOMETRY_STORAGE value for the default is SDEBINARY. Under the DEFAULTS keyword in the dbtune.sde file, the GEOMETRY_STORAGE is set to SDEBINARY.
##DEFAULTS
GEOMETRY_STORAGE "SDEBINARY"
<other parameters>
END
You can change the default GEOMETRY_STORAGE in a geodatabase in SQL Server to use the Open Geospatial Consortium, Inc. (OGC), Well-Known Binary storage data type by changing the value of the GEOMETRY_STORAGE parameter of the DEFAULTS keyword to OGCWKB. For a description of this data type, see The OGC Well-Known Binary representation for geometry.
If you have changed your DEFAULTS GEOMETRY_STORAGE to OGCWKB but want to create some of your feature classes with ArcSDE Compressed Binary, you could create a configuration keyword to specify when you create specific feature classes. For example, in the dbtune.sde file, such a configuration keyword might appear as follows:
##SDEBINARY
GEOMETRY_STORAGE "SDEBINARY"
UI_TEXT ""
COMMENT "Used to create feature classes with SDEBINARY geometry storage"
END
For information on creating DBTUNE keywords, see DBTUNE configuration keywords.
For geodatabases stored in Oracle, ArcSDE Compressed Binary geometry can be stored as either a binary large object (BLOB) or LONG RAW data type. ArcSDE geodatabases in Oracle use ST_Geometry storage by default, so if you want to store most of your geometry in ArcSDE Compressed Binary format, you need to alter the DEFAULTS GEOMETRY_STORAGE parameter to either SDEBINARY, which is the ArcSDE Compressed Binary geometry stored as a LONG RAW data type, or to SDELOB, which is the ArcSDE Compressed geometry stored as a BLOB. For information on tuning storage of BLOBs in a geodatabase stored in Oracle, see the Oracle section of Minimize disk I/O contention in Oracle.
NOTE: Oracle has deprecated the LONG RAW storage type. For this reason, it is recommended that you not use SDEBINARY storage for new feature classes.
If you want to have a mix of geometry types in your ArcSDE geodatabase for Oracle, you can leave the DEFAULTS GEOMETRY_STORAGE parameter set to ST_GEOMETRY, then specify other configuration keywords to be used when you create particular feature classes. Available keywords are SDELOB, SDO_GEOMETRY, SDEBINARY, and WKB_GEOMETRY.
