GIS Group
WYDOT Content Standards for Data Knowledge Base (Sept 5, 2000)
Geographic Information Systems Oversight Committee
Technical Advisory Group
Sept 5, 2000
Definition: A Data Knowledge Base is a collection of metadata, or "data about data". It describes the content and other characteristics of data. The Data Knowledge Base helps a person locate and understand data within the databases at the Wyoming Department of Transportation (WYDOT).
Major uses of the Data Knowledge Base:
- Organize and maintain WYDOT's investment in data. A Data Knowledge Base helps insure WYDOT's investment in data. As personnel change or time passes, information about WYDOT's data will be lost and the data may lose their value. Later workers may have little understanding of the content and uses for a digital database and may find that they can't trust results generated from these data. Complete metadata descriptions of the content of a database will encourage appropriate use of the data. Such descriptions may provide some protection for WYDOT if conflicts arise over the misuse of data.
- Provide information to aid data transfer. Metadata from the Data Knowledge Base should accompany the transfer of a data set. The metadata will aid the organization receiving the data to process, interpret, and incorporate data into its holdings.
About the Standard: This standard specifies the elements needed to support the above uses. It establishes a common set of terminology and definitions for concepts related to metadata, including:
- The names of data elements and compound elements (groups of data elements) to be used.
- The definitions of these compound and data elements.
- The information about the values that are to be provided for the data elements.
The standard also specifies the elements that are mandatory (must be provided), mandatory if applicable (must be provided if the data set exhibits the defined characteristics), and mandatory if new, optional if existing (must be provided for a newly created data set or provided at the discretion of the producer for an existing data set).
The standard specifies information content, but not how to organize this information in a computer system or in a data transfer, or how to transmit, communicate, or present the information to a user. There are a large number of methods to transmit, communicate, and present metadata. Different metadata elements will be valued by different users, or by one user for different tasks. The Internet and other technologies are causing rapid change in means to providing information. Many users continue to need or prefer metadata to be provided on physical media, including paper. The standard allows WYDOT to use the techniques and forms which best meet the needs of its users.
Data Knowledge Base Information
1 Organization
- The program/division/office responsible for the stewardship of the database.
- Type: text
- Domain: free text
- Status: required
- Domain: free text
- Type: text
2 Database Information
- Repeat as necessary.
2.1 Table Name
- The name of the table.
- Type: text
- Domain: free text
- Status: required
- Domain: free text
- Type: text
2.2 Table Information
- Repeat as necessary.
2.2.1 Column Name
- The name of the column.
- Type: text
- Domain: free text
- Status: required
- Domain: free text
- Type: text
2.2.2 Column Definition
- A description of the column.
- Type: text
- Domain: free text
- Status: required
- Domain: free text
- Type: text
2.2.3 Column Definition Source
- The authority of the definition.
- Type: text
- Domain: free text
- Status: required
- Domain: free text
- Type: text
2.2.4 Data Type
- The data type of the column values.
- Type: text
- Domain: "CHAR", "VARCHAR2", "NUMBER", "DATE", "FLOAT"
- Status: required
- Domain: "CHAR", "VARCHAR2", "NUMBER", "DATE", "FLOAT"
- Type: text
2.2.5 Length
- The number of places wide of the column.
- Type: integer
- Domain: free integer
- Status: required
- Domain: free integer
- Type: integer
2.2.6 Precision
- The number of decimal places for a number data type column.
- Type: integer
- Domain: free integer
- Status: mandatory if applicable
- Domain: free integer
- Type: integer
2.2.7 Nulls Allowed
- Specifies if null values are allowed in the column.
- Type: text
- Domain: "Yes", "No"
- Status: required
- Domain: "Yes", "No"
- Type: text
2.2.8 Key Type
- Specifies the type of key.
- Type: text
- Domain: "Primary", "Primary i of n", "Secondary", "Secondary i of n"
- Status: mandatory if applicable
- Domain: "Primary", "Primary i of n", "Secondary", "Secondary i of n"
- Type: text
2.2.9 Related Tables
- The tables that are connected to the column based on the key type.
- Type: text
- Domain: free text
- Status: mandatory if applicable
- Domain: free text
- Type: text
2.2.10 Domain Information
- Repeat as necessary
2.2.10.1 Enumerated Domain Information
- The members of an established set of valid values. Repeat as necessary.
- Status: mandatory if applicable
2.2.10.1.1 Enumerated Domain Value
- The name or label of a member of the set.
- Type: text
- Domain: free text
- Status: required
- Domain: free text
- Type: text
2.2.10.1.2 Enumerated Domain Value Definition
- The description of the value.
- Type: text
- Domain: free text
- Status: required
- Domain: free text
- Type: text
2.2.10.1.3 Enumerated Domain Value Definition Source
- The authority of the definition.
- Type: text
- Domain: free text
- Status: required
- Domain: free text
- Type: text
2.2.10.1.4 Beginning Date of Enumerated Domain Value
- Earliest or only date for which the value is current. In cases when a range of dates are provided, this is the earliest date for which the information are valid.
- Type: date
- Domain: free date
- Status: required if new, optional if existing
- Domain: free date
- Type: date
2.2.10.1.5 Ending Date of Enumerated Domain Value
- Latest date for which the information are current. Used in cases when a range of dates are provided.
- Type: date
- Domain: free date
- Status: mandatory if applicable
- Domain: free date
- Type: date
2.2.10.2 Range Domain
- The minimum and maximum values of a continuum.
- Status: mandatory if applicable.
2.2.10.2.1 Range Domain Minimum
- The least value that the column values can be assigned.
- Type: text
- Domain: free text
- Status: required
- Domain: free text
- Type: text
2.2.10.2.2 Range Domain Maximum
- The greatest value that the column values can be assigned.
- Type: text
- Domain: free text
- Status: required
- Domain: free text
- Type: text
2.2.10.3 Codeset Domain
- Reference to a standard or list which contains the members of an established set of valid values.
- Status: mandatory if applicable
2.2.10.3.1 Codeset Name
- The title of the codeset.
- Type: text
- Domain: free text
- Status: required
- Domain: free text
- Type: text
2.2.10.3.2 Codeset Source
- The authority of the codeset.
- Type: text
- Domain: free text
- Status: required
- Domain: free text
- Type: text
2.2.10.4 Unrepresentable Domain
- Description of the values and reasons why they cannot be represented.
- Type: text
- Domain: free text
- Status: mandatory if applicable.
- Domain: free text
- Type: text
2.2.11 Units
- The standard of measurement for the column values.
- Type: text
- Domain: free text
- Status: mandatory if applicable
- Domain: free text
- Type: text
2.2.12 Beginning Date of Column
- Earliest or only date for which the column is current. In cases when a range of dates are provided, this is the earliest date for which the information are valid.
- Type: date
- Domain: free date
- Status: required if new, optional if existing
- Domain: free date
- Type: date
2.2.13 Ending Date of Column
- Latest date for which the information are current. Used in cases when a range of dates are provided.
- Type: date
- Domain: free date
- Status: mandatory if applicable
- Domain: free date
- Type: date
2.3 Contact
- The person within the Organization responsible for the stewardship of the table.
- Type: text
- Domain: free text
- Status: required
- Domain: free text
- Type: text
2.4 Beginning Date of Table
- Earliest or only date for which the table is current. In cases when a range of dates are provided, this is the earliest date for which the information are valid.
- Type: date
- Domain: free date
- Status: required if new, optional if existing
- Domain: free date
- Type: date
2.5 Ending Date of Table
- Latest date for which the information are current. Used in cases when a range of dates are provided.
- Type: date
- Domain: free date
- Status: mandatory if applicable
- Domain: free date
- Type: date
2.6 Users
- Other organizations who currently use the table.
- Type: text
- Domain: free text
- Status: required
- Domain: free text
- Type: text
Notes:
What is a domain?
A domain is the set of possible data values of a column.
What is an enumerated domain?
An enumerated domain is one comprised of a list of values. For example, a "road type" column can have an enumerated domain which contains the values "heavy duty", "medium duty", "light duty", and "trail". In this case, the list of possible values, the definitions of the values, and the sources of the definitions should be provided.
What is a range domain?
A range domain is comprised of a sequence, series, or scale of (usually numeric) values between limits. For example, a column of age values might have a range domain of integers from 0 to 100. In this case, the minimum and maximum values should be provided.
What is a codeset domain?
A codeset domain is one in which the data values are defined by a set of codes. Examples include the Federal Information Processing Standards that contain numeric codes for nations, States, and counties. In this case, the title of the publication containing the code set and the source of the codeset should be provided.
What is an unrepresentable domain?
An unrepresentable domain is one for which the set of data values cannot be represented. Reason include columns whose values do not exist in a known, predefined set (for example, the values for a column of people's names), or columns whose values cannot be depicted using forms of representation (available character set, etc.) used for the Data Knowledge Base. In these cases, the information content of the set of values should be provided.
