Feature classes in a geodatabase in Oracle

Feature classes in a geodatabase in Oracle
Release 9.3

Feature classes in ArcCatalog

Feature class tables in an Oracle database stored with ST_Geometry storage

NOTE: Creating a table with an ST_Geometry column does not insert ST_Geometry metadata. It is your (or the application's) responsibility to register this metadata information.

Feature class tables in an Oracle database stored with binary geometry storage

• The business table
Under the binary schema implementation, the spatial column in the business table contains a feature ID that uniquely references the spatial data. The feature ID joins the business table to two other tables: the feature and spatial index tables.
In the USACOUNTIES table example, the two required fields are the OBJECTID and SHAPE field. (These fields can have different names, but they must store the OBJECTID and SHAPE information.) Annotation and dimension feature classes have additional required fields in their business tables. See Managing annotation feature class properties for a list of these fields.
A database trigger is defined on the spatially enabled, nonversioned business table to maintain the relationship between records in the business table and the feature table.
All nonversioned feature class business tables have a cascade delete trigger, which ensures that if you delete the spatial column in the business table, it is deleted from the feature table. You can view these triggers in the Oracle Enterprise Manager.
These triggers are automatically dropped whenever a feature class, either stand-alone or in a feature dataset, is multiversioned. They are re-created when a feature class is unregistered as versioned. If you edit one of these triggers, then multiversion the feature class, the trigger will be dropped.
• The feature table (F<layer_id>)
The feature table stores the geometric shapes for each feature. This table is identified by the number in the layer_id column of the LAYERS table. The relationship between the business table and the feature table is managed through the Feature ID, or FID. This key, which is maintained by ArcSDE, is unique for the spatial column. In the example above, the feature table is F115.



Field name	Field type	Description
FID	NUMBER(38)	Primary key; the unique ID that joins the feature table to the business table NOT NULL
NUMOFPTS	NUMBER(38)	The number of points defining the feature NOT NULL
ENTITY	NUMBER(38)	The type of geometry stored in the spatial column (for example, point, line, or string) NOT NULL
EMINX	FLOAT(64)	The minimum x-value in a feature; with eminy, emaxx, and emaxy, defines the envelope of a feature NOT NULL
EMINY	FLOAT(64)	The minimum y-value in a feature; with eminx, emaxx, and emaxy, defines the envelope of a feature NOT NULL
EMAXX	FLOAT(64)	The maximum x-value in a feature; with eminx, eminy, and emaxy, defines the envelope of a feature NOT NULL
EMAXY	FLOAT(64)	The maximum y-value in a feature; with eminx, eminy, and emaxx, defines the envelope of a feature NOT NULL
EMINZ	FLOAT(64)	The minimum z-value in a three-dimensional feature
EMAXZ	FLOAT(64)	The maximum z-value in a three-dimensional feature
MIN_MEASURE	FLOAT(64)	The minimum measure value in a feature
MAX_MEASURE	FLOAT(64)	The maximum measure value in a feature; nulls allowed
AREA	FLOAT(64)	The area of the geometry
LEN	FLOAT(64)	The length or perimeter of the geometry
POINTS	LONG RAW	Contains the byte stream of point coordinates that define the geometry

As features are inserted or updated, values for such columns as extents and numofpts are recalculated automatically.
The relationship between the business table and the feature table is managed through the spatial column and the FID column. This key, which is maintained by ArcSDE, is unique.
Maintaining the referential integrity between the business and feature table is important. You should not edit the records of either the feature table or the spatial index table. Several indexes and constraints have been added to the business, feature, and spatial index table to ensure referential integrity is maintained. However, these indexes and constraints are removed when the feature class is converted to the load-only I/O mode, a state that allows for rapid insertion of data into the feature class.
When the feature class is placed back into normal I/O mode—the state that allows users to query the feature class through an ArcSDE client—the indexes are created and the constraints are enabled. The conversion to normal I/O mode will fail if the unique indexes cannot be built on the business table's spatial column or the feature table's FID column. It will also fail if a value exists in the business table's spatial column that is not in the feature table's FID column. In this case, a reference to the offending business table record is loaded into the SDE_EXCEPTIONS table.
The feature table stores the geometry, annotation, and computer-aided design (CAD) elements in the POINTS column. The POINTS column may be defined as either BLOB or LONG RAW depending on the setting of the GEOMETRY_STORAGE DBTUNE storage parameter. Set the GEOMETRY_STORAGE DBTUNE storage parameter to SDEBINARY if you want to store the compressed binary spatial data in a column defined as LONG RAW; otherwise, set the storage parameter to SDELOB if you want to store the compressed binary spatial data in a column defined as BLOB.
• The spatial index table (S<layer_id>)
The spatial index of the binary implementation is the spatial index table. It stores references to shapes based on a simple, regular grid. This table is identified by the number in the layer_id column in the LAYERS table. In the Parcels feature class example, the spatial index table is S115.
(Note that the spatial index table for binary feature classes is related to the LAYER_ID value in the LAYERS table, whereas the spatial index table for ST_Geometry feature classes is related to the INDEX_ID generated in the ST_GEOMETRY_INDEX table.)
The spatial index contains an entry for each shape and grid cell combination to support spatial queries. A feature that crosses into three grid cells has three entries in the table. When a spatial query is performed, the grid cells within the search area are identified and used to return a list of candidate geometries.



Field name	Field type	Description
SP_FID	NUMBER(38)	Primary key; the unique ID that joins the spatial index table to the business table NOT NULL
GX	NUMBER(38)	The spatial index grid x-value NOT NULL
GY	NUMBER(38)	The spatial index grid y-value NOT NULL
EMINX	NUMBER(38)	The minimum x-value in a feature; with eminy, emaxx, and emaxy, defines the envelope of a feature NOT NULL
EMINY	NUMBER(38)	The minimum y-value in a feature; with eminx, emaxx, and emaxy, defines the envelope of a feature NOT NULL
EMAXX	NUMBER(38)	The maximum x-value in a feature; with eminx, eminy, and emaxy, defines the envelope of a feature NOT NULL
EMAXY	NUMBER(38)	The maximum y-value in a feature; with eminx, eminy, and emaxx, defines the envelope of a feature NOT NULL

The spatial index table defines the grid range and extent of all geometry in an ArcSDE feature class.
• sp_fid—Contains the unique ID that joins the feature table to the business table
• gx/gy—Defines the feature's extent in grid cells
• eminx/eminy/emaxx/emaxy—Defines the extent of the feature in system units
In this example, the FEATURE-ID column from the WELLS business table references features from the feature and spatial index tables:

WELL_ID	DEPTH	ACTIVE	FEATURE-ID
1	30029	Yes	101
2	13939	No	102
3	92891	No	103
………

FID
AREA	LEN	EMINX,EMINY,…	POINTS
101				<compressed feature>
102				<compressed feature>
103				<compressed feature>
……

SP_FID	GX	GY	{EMINX,EMINY,EMAXX,EMAXY}
101	70	100	
102	70	100	
103	71	100	
…
        A business/feature/spatial index key reference

Feature class tables in an Oracle database stored in Oracle Spatial geometry storage

Feature classes in an XML document

<esri:Workspace xmlns:esri="http://www.esri.com/schemas/ArcGIS/9.2" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xs="http://www.w3.org/2001/XMLSchema">
  <WorkspaceDefinition xsi:type="esri:WorkspaceDefinition">
     <WorkspaceType>esriRemoteDatabaseWorkspace</WorkspaceType> 
     <Version>SDE.DEFAULT</Version> 
     <Domains xsi:type="esri:ArrayOfDomain" /> 
     <DatasetDefinitions xsi:type="esri:ArrayOfDataElement">
        <DataElement xsi:type="esri:DEFeatureClass">
           <CatalogPath>/V=SDE.DEFAULT/FC=VENUS.USACOUNTIES</CatalogPath> 
           <Name>VENUS.USACOUNTIES</Name> 
           <DatasetType>esriDTFeatureClass</DatasetType> 
           <DSID>-1</DSID> 
           <Versioned>false</Versioned> 
           <CanVersion>true</CanVersion> 
           <HasOID>true</HasOID> 
           <OIDFieldName>FEATURE.FID</OIDFieldName> 
           <Fields xsi:type="esri:Fields">
              <FieldArray xsi:type="esri:ArrayOfField">
                 <Field xsi:type="esri:Field">
                    <Name>NAME</Name> 
                    <Type>esriFieldTypeString</Type> 
                    <IsNullable>true</IsNullable> 
                    <Length>32</Length> 
                    <Precision>0</Precision> 
                    <Scale>0</Scale> 
              </Field>
              <Field xsi:type="esri:Field">
                 <Name>STATE_NAME</Name> 
                 <Type>esriFieldTypeString</Type> 
                 <IsNullable>true</IsNullable> 
                 <Length>25</Length> 
                 <Precision>0</Precision> 
                 <Scale>0</Scale> 
             </Field>
             <Field xsi:type="esri:Field">
                <Name>VENUS.USACOUNTIES.AREA</Name> 
                <Type>esriFieldTypeDouble</Type> 
                <IsNullable>true</IsNullable> 
                <Length>8</Length> 
                <Precision>22</Precision> 
                <Scale>4</Scale> 
             </Field>
             <Field xsi:type="esri:Field">
                <Name>POP1997</Name> 
                <Type>esriFieldTypeInteger</Type> 
                <IsNullable>true</IsNullable> 
                <Length>4</Length> 
                <Precision>10</Precision> 
                <Scale>0</Scale> 
             </Field>

Subtypes are used to differentiate feature types within a feature class based on their default values, attribute domains, connectivity rules, and relationship rules. Subtypes are defined for a feature class, and only one field in the feature class can have subtypes defined for it.

Subtypes in ArcCatalog

Since subtypes are defined on the feature class, you define and view subtypes in ArcCatalog from the Feature Class Properties dialog box. Right-click the feature class, click Properties, and click the Subtypes tab to see the following dialog box:

This example shows subtypes applied to the TYPECODE field for a feature class called Laterals. You see the codes used for the subtypes, the descriptions (names) of the subtypes, and the default subtype for the TYPECODE field in the Laterals feature class.

Subtypes in an Oracle DBMS

The following is a diagram of the tables used for subtypes applied to a feature class:

The subtypes for feature classes are tracked in the GDB_SUBTYPE system table, the default values for the subtypes are tracked in the GDB_DEFAULTVALUES system table, and the fields to which these apply are tracked in the GDB_FIELDINFO system table. The subtypes are associated to the feature class by way of the GDB_OBJECTCLASSES table. The GDB_DEFAULTVALUES table is associated with the GDB_SUBTYPES table by the subtype code, which is stored in the SubtypeCode field in the GDB_SUBTYPES table and the Subtype field in the GDB_DEFAULTVALUES table.

The name of the field to which the subtype applies is stored in the SUBTYPEFIELD column of the GDB_OBJECTCLASSES table. This field is linked to the FIELDNAME column in the GDB_FIELDINFO table, which in turn is associated to the FIELDNAME column in the GDB_DEFAULTVALUES table.

Subtypes in an XML document

Subtypes appear in XML documents as part of the information for the feature class. They are grouped under a Subtypes tag. For the Laterals example, the subtype information in an XML document is as follows:

- <Subtypes xsi:type="esri:ArrayOfSubtype">
  <Subtype xsi:type="esri:Subtype">
      <SubtypeName>Unknown</SubtypeName> 
      <SubtypeCode>0</SubtypeCode> 
    <FieldInfos xsi:type="esri:ArrayOfSubtypeFieldInfo">
      <SubtypeFieldInfo xsi:type="esri:SubtypeFieldInfo">
          <FieldName>H_CONFID</FieldName> 
          <DefaultValue xsi:type="xs:int">0</DefaultValue> 
        </SubtypeFieldInfo>
      <SubtypeFieldInfo xsi:type="esri:SubtypeFieldInfo">
          <FieldName>DIAMETER</FieldName> 
          <DomainName>LatDiameter</DomainName> 
          <DefaultValue xsi:type="xs:double">8</DefaultValue> 
        </SubtypeFieldInfo>
      <SubtypeFieldInfo xsi:type="esri:SubtypeFieldInfo">
          <FieldName>DEPTH_BURI</FieldName> 
          <DefaultValue xsi:type="xs:double">0</DefaultValue> 
        </SubtypeFieldInfo>
      <SubtypeFieldInfo xsi:type="esri:SubtypeFieldInfo">
          <FieldName>RECORDED_L</FieldName> 
          <DefaultValue xsi:type="xs:double">0</DefaultValue> 
        </SubtypeFieldInfo>
      <SubtypeFieldInfo xsi:type="esri:SubtypeFieldInfo">
          <FieldName>WNM_TYPE</FieldName> 
          <DefaultValue xsi:type="xs:string">WUNKNOWN</DefaultValue> 
        </SubtypeFieldInfo>
      <SubtypeFieldInfo xsi:type="esri:SubtypeFieldInfo">
          <FieldName>PWTYPE</FieldName> 
          <DefaultValue xsi:type="xs:string">WUNKNOWN</DefaultValue> 
        </SubtypeFieldInfo>
      <SubtypeFieldInfo xsi:type="esri:SubtypeFieldInfo">
          <FieldName>MATERIAL</FieldName> 
          <DomainName>Material</DomainName> 
          <DefaultValue xsi:type="xs:string">DI</DefaultValue> 
        </SubtypeFieldInfo>
      <SubtypeFieldInfo xsi:type="esri:SubtypeFieldInfo">
          <FieldName>TYPECODE</FieldName> 
          <DefaultValue xsi:type="xs:int">3</DefaultValue> 
        </SubtypeFieldInfo>
      <SubtypeFieldInfo xsi:type="esri:SubtypeFieldInfo">
          <FieldName>ENABLED</FieldName> 
          <DomainName>EnabledDomain</DomainName> 
          <DefaultValue xsi:type="xs:short">1</DefaultValue> 
        </SubtypeFieldInfo>
     </FieldInfos>
  </Subtype>
<Subtype xsi:type="esri:Subtype">
    <SubtypeName>Hydrant laterals</SubtypeName> 
    <SubtypeCode>1</SubtypeCode> 
  <FieldInfos xsi:type="esri:ArrayOfSubtypeFieldInfo">
      <SubtypeFieldInfo xsi:type="esri:SubtypeFieldInfo">
          <FieldName>H_CONFID</FieldName> 
          <DefaultValue xsi:type="xs:int">0</DefaultValue> 
        </SubtypeFieldInfo>
      <SubtypeFieldInfo xsi:type="esri:SubtypeFieldInfo">
          <FieldName>DIAMETER</FieldName> 
          <DomainName>LatDiameter</DomainName> 
          <DefaultValue xsi:type="xs:double">8</DefaultValue> 
        </SubtypeFieldInfo>
      <SubtypeFieldInfo xsi:type="esri:SubtypeFieldInfo">
          <FieldName>DEPTH_BURI</FieldName> 
          <DefaultValue xsi:type="xs:double">0</DefaultValue> 
        </SubtypeFieldInfo>
      <SubtypeFieldInfo xsi:type="esri:SubtypeFieldInfo">
          <FieldName>RECORDED_L</FieldName> 
          <DefaultValue xsi:type="xs:double">0</DefaultValue> 
        </SubtypeFieldInfo>
      <SubtypeFieldInfo xsi:type="esri:SubtypeFieldInfo">
          <FieldName>WNM_TYPE</FieldName> 
          <DefaultValue xsi:type="xs:string">WHYDLIN</DefaultValue> 
        </SubtypeFieldInfo>
      <SubtypeFieldInfo xsi:type="esri:SubtypeFieldInfo">
          <FieldName>PWTYPE</FieldName> 
          <DefaultValue xsi:type="xs:string">WHYDLIN</DefaultValue> 
        </SubtypeFieldInfo>
      <SubtypeFieldInfo xsi:type="esri:SubtypeFieldInfo">
          <FieldName>MATERIAL</FieldName> 
          <DomainName>Material</DomainName> 
          <DefaultValue xsi:type="xs:string">DI</DefaultValue> 
        </SubtypeFieldInfo>
      <SubtypeFieldInfo xsi:type="esri:SubtypeFieldInfo">
          <FieldName>ENABLED</FieldName> 
          <DomainName>EnabledDomain</DomainName> 
          <DefaultValue xsi:type="xs:short">1</DefaultValue> 
        </SubtypeFieldInfo>
     </FieldInfos>
  </Subtype>
<Subtype xsi:type="esri:Subtype">
    <SubtypeName>Fire laterals</SubtypeName> 
    <SubtypeCode>2</SubtypeCode> 
  <FieldInfos xsi:type="esri:ArrayOfSubtypeFieldInfo">
      <SubtypeFieldInfo xsi:type="esri:SubtypeFieldInfo">
          <FieldName>H_CONFID</FieldName> 
          <DefaultValue xsi:type="xs:int">0</DefaultValue> 
        </SubtypeFieldInfo>
      <SubtypeFieldInfo xsi:type="esri:SubtypeFieldInfo">
          <FieldName>DIAMETER</FieldName> 
          <DomainName>LatDiameter</DomainName> 
          <DefaultValue xsi:type="xs:double">8</DefaultValue> 
        </SubtypeFieldInfo>
      <SubtypeFieldInfo xsi:type="esri:SubtypeFieldInfo">
          <FieldName>DEPTH_BURI</FieldName> 
          <DefaultValue xsi:type="xs:double">0</DefaultValue> 
        </SubtypeFieldInfo>
      <SubtypeFieldInfo xsi:type="esri:SubtypeFieldInfo">
          <FieldName>RECORDED_L</FieldName> 
          <DefaultValue xsi:type="xs:double">0</DefaultValue> 
        </SubtypeFieldInfo>
      <SubtypeFieldInfo xsi:type="esri:SubtypeFieldInfo">
          <FieldName>WNM_TYPE</FieldName> 
          <DefaultValue xsi:type="xs:string">WFIRELIN</DefaultValue> 
        </SubtypeFieldInfo>
      <SubtypeFieldInfo xsi:type="esri:SubtypeFieldInfo">
          <FieldName>PWTYPE</FieldName> 
          <DefaultValue xsi:type="xs:string">WFIRELIN</DefaultValue> 
        </SubtypeFieldInfo>
      <SubtypeFieldInfo xsi:type="esri:SubtypeFieldInfo">
          <FieldName>MATERIAL</FieldName> 
          <DomainName>Material</DomainName> 
         <DefaultValue xsi:type="xs:string">DI</DefaultValue> 
        </SubtypeFieldInfo>
      <SubtypeFieldInfo xsi:type="esri:SubtypeFieldInfo">
          <FieldName>ENABLED</FieldName> 
          <DomainName>EnabledDomain</DomainName> 
          <DefaultValue xsi:type="xs:short">1</DefaultValue> 
        </SubtypeFieldInfo>
     </FieldInfos>
  </Subtype>
<Subtype xsi:type="esri:Subtype">
    <SubtypeName>Service laterals</SubtypeName> 
    <SubtypeCode>3</SubtypeCode> 
  <FieldInfos xsi:type="esri:ArrayOfSubtypeFieldInfo">
      <SubtypeFieldInfo xsi:type="esri:SubtypeFieldInfo">
          <FieldName>H_CONFID</FieldName> 
          <DefaultValue xsi:type="xs:int">0</DefaultValue> 
        </SubtypeFieldInfo>
      <SubtypeFieldInfo xsi:type="esri:SubtypeFieldInfo">
          <FieldName>DIAMETER</FieldName> 
          <DomainName>LatDiameter</DomainName> 
          <DefaultValue xsi:type="xs:double">8</DefaultValue> 
        </SubtypeFieldInfo>
      <SubtypeFieldInfo xsi:type="esri:SubtypeFieldInfo">
          <FieldName>DEPTH_BURI</FieldName> 
          <DefaultValue xsi:type="xs:double">0</DefaultValue> 
        </SubtypeFieldInfo>
      <SubtypeFieldInfo xsi:type="esri:SubtypeFieldInfo">
          <FieldName>RECORDED_L</FieldName> 
          <DefaultValue xsi:type="xs:double">0</DefaultValue> 
        </SubtypeFieldInfo>
      <SubtypeFieldInfo xsi:type="esri:SubtypeFieldInfo">
          <FieldName>WNM_TYPE</FieldName> 
          <DefaultValue xsi:type="xs:string">WSERVICE</DefaultValue> 
        </SubtypeFieldInfo>
      <SubtypeFieldInfo xsi:type="esri:SubtypeFieldInfo">
          <FieldName>PWTYPE</FieldName> 
          <DefaultValue xsi:type="xs:string">WSERVICE</DefaultValue> 
       </SubtypeFieldInfo>
     <SubtypeFieldInfo xsi:type="esri:SubtypeFieldInfo">
          <FieldName>MATERIAL</FieldName> 
          <DomainName>Material</DomainName> 
          <DefaultValue xsi:type="xs:string">DI</DefaultValue> 
        </SubtypeFieldInfo>
      <SubtypeFieldInfo xsi:type="esri:SubtypeFieldInfo">
          <FieldName>ENABLED</FieldName> 
          <DomainName>EnabledDomain</DomainName> 
          <DefaultValue xsi:type="xs:short">1</DefaultValue> 
        </SubtypeFieldInfo>
     </FieldInfos>
   </Subtype>
 </Subtypes>