| Name | Meta_Attribute |
|---|---|
| Entity Type | External |
| Description | The attributes of an Entity are described via the Meta_Attribute table. |
| Submodel | Meta |
| Entity Scope | Meta |
| Primary Key | Entity , Attribute |
| Natural Key | Entity , Attribute |
| Generalizations | |
| Specializations |
| Name | Value Domain | Property / Storage Unit | Description | Required / Default | Type |
|---|---|---|---|---|---|
| Attribute |
|
Physical name of property in database. Maximum length of 30 because of Oracle. This is the name exposed via public SQL interface. | Yes |
VARCHAR2(30) | |
| Attribute_Nr |
|
Physical definition order of attributes. Automatically populated by the meta-system. Not currently exploited. | No |
NUMBER(3) | |
| Changeable |
|
Is this property changeable? 0 => Read Only; 1 => Frozen -- set once during insert; 2 => Changeable | No |
NUMBER(1) | |
| Check_Constraint |
|
A la Oracle Derived from R_Value_Domain? It is currently ignored. | No |
VARCHAR2(1000) | |
| DB_Type |
|
Database type (e.g., VARCHAR2(64), DATE, NUMBER). Cached. It may be derived from R_Value_Domain. SQL Server vs Oracle issue here to be resolved. Use of Value_Domain should eventually replace use of DB_TYPE. | No |
VARCHAR2(64) | |
| Default_Value |
|
Implemented at what level? Table, view, or triggers? Only used for default value of Sub_Type today. | No |
VARCHAR2(64) | |
| Description |
|
Long description of the Attribute. Primary purpose is for documentation in Web Report. | No |
VARCHAR2(2000) | |
| Entity | Meta_Entity |
|
Foreign Key to Meta_Entity | Yes |
VARCHAR2(25) |
| Eval_Method |
|
Name of evaluation method for derived attributes. Set by .Depend Default for attribute XYZ is Eval_XYZ. | No |
VARCHAR2(30) | |
| Hand_Down |
|
Specifies that this table attribute is not to appear in any view, including the standard view of the base table, unless explicitly declared. | No |
NUMBER(1) | |
| Implementation_Technique |
|
Specifies how this attribute is implemented. Enumeration Values: Column: normal relational column. Prop: light-weight Parameter; not currently used. Default value is Column. | No |
VARCHAR2(32) | |
| Join_Rule |
|
Specifies a links relationship. See Meta_Link.Join_Rule for details. Populated when Links are reflected into Meta_Attribute. | No |
VARCHAR2(10) | |
| Mandatory |
|
Is this property mandatory? GeoFrame had concept of "Recommended" that was checked in QC Tool. This could be represented by -1. | No |
NUMBER(1) | |
| Measurement |
|
E.g., Porosity This can be a sub-dimension (e.g., ShortLength). If this is provided, default Value_Domain = Number. | No |
VARCHAR2(64) | |
| Name |
|
Logical Name of the property. Default value is Attribute replacing spaces by underscores. Appropriate for display purposes. | No |
VARCHAR2(64) | |
| Property |
|
Reference to SDM Property Catalog. It can be used to extract defaults for other facets. Do we still want this? Not exploited today. | No |
VARCHAR2(64) | |
| Unit |
|
Storage Unit (from OSDD). Derived from Measurement. | No |
VARCHAR2(64) | |
| Value_Domain |
|
This is general mechanism to map to types in underlying system. Use of Value_Domain should eventually replace use of DB_TYPE. It is currently used to map to Oracle, SQL Server. It may eventually be used to map to ADI, Java, C#. E.g., RGB_COLOR | No |
VARCHAR2(64) |
| Link | To Entity | Description | Implementation Technique | Required |
|---|---|---|---|---|
| Entity | Meta_Entity | Foreign Key to Meta_Entity | Restrict | Yes |