Dimension Column Properties

Each dimension column has a set of associated properties. The definition of each property is described below:

If a database table's definition is changed in the metadata, then the table needs to be altered in the database. Use the Validate > Validate Table Create Status to compare metadata definitions to physical database tables. The option also provides the ability to alter the database table, through a pop-up menu option from the validated table name. See the example below.

A sample Properties screen is as follows:

The two special update keys enable you to update the column and step either forward or backward to the next column's properties. ALT-Left Arrow and ALT-Right Arrow can also be used instead of the two special update keys

General

Options	Description
Table Name	Database-compliant name of the table that contains the column. [Read-only].
Column Name	Database-compliant name of the column. Typically column-naming standards exclude the use of spaces etc. A good practice is to only use alphanumerics and the underscore character. Changing this field alters the table's definition. The case conversion button on the right converts the text between different cases: UPPER CASE, Capitalized Case, and lower case. The mode cycles to the next case in the sequence of each conversion.
Business Display Name / Column Title	Name that the business uses refers to the column, which is included in the RED-generated documentation and can be used in the end-user layer of other tools. [Does NOT affect the physical database table]. As such it is a free-form entry and any characters are valid. The case conversion button on the right converts the text between different cases: UPPER CASE, Capitalized Case, and lower case. The mode cycles to the next case in the sequence of each conversion.
Column Description	This field contains the description for the column. It may be a description from a business user's point of view. This field might additionally contain information on where and how the column was acquired. For example, if the column is sourced from multiple tables or is a composite or derived column then this definition would normally describe the process used to populate the column. This field is used in the documentation and is available via the view ws_admin_v_dim_col . This field is also stored as a comment against the column in the database.

Physical Definition

Options	Description
Column Order	Numeric value that controls the relative order of columns in the database create statement. The lowest-numbered column will appear first in the table. Although this affects the physical table definition no action will be taken unless the table is re-created in the database. The columns can be re-numbered based on the existing order by choosing the Respace Order Number pop-up menu option when positioned over any column in the table. This action will number the columns in increments of 10 starting at 10. In addition to a simple change of the order field, the column order can be changed by first displaying the columns in the middle pane and then using drag and drop to move the columns around. This drag-and-drop process will automatically renumber the columns as required.
Data Type	Database-compliant data type that must be valid for the target database. See the database documentation for a description of the data types available. Changing this field alters the table's definition.
Null Values Allowed	Determines whether the table column can hold NULL values or whether a value is always mandatory.
Default Value	Initial value that is assigned to the column when a row is inserted into the table but no value is specified for the column.

Meta Definition

Options

Description

Format

Optional format mask that can be used in end-user tools. [Does NOT affect the physical database table]. As such it is a free-form entry and any characters are valid. Typically format masks are only used on numeric fields. Example: #,###0.00. It is not worth the effort of populating this field unless it can be utilized by the end-user tools in use.

Numeric

Indicates whether the table column holds numeric values. This is normally only relevant for fact tables. It does not affect the physical table definition but rather provides input to the view ws_admin_v_dim_col which can be used to assist in the population of an end user tool's end user layer. The use of this field is not relevant unless it can be utilized by the end-user tools.

Additive

Indicates whether the table column holds values that are additive. This implies that the column can be summed when performing data grouping in a query. This is normally only relevant for fact tables. It does not affect the physical table definition but rather provides input to the view ws_admin_v_dim_col which can be used to assist in the population of an end user tool's end user layer. The use of this field is not relevant unless it can be utilized by the end-user tools.

Attribute

Indicates whether the table column holds values that are descriptive, and/or are used for grouping/summing. An attribute is defined as a non-factual column. For example, we may have an order number or an invoice number stored in the fact table. Such columns are considered attributes, rather than facts. This checkbox is therefore normally only relevant for fact tables.
This check box does not affect the physical table definition but rather provides input to the view ws_admin_v_dim_col which can be used to assist in the population of an end user tools end user layer. The use of this field is not relevant unless it can be utilized by the end-user tools.

End User Layer Display

Indicates whether the table column is available/visible to end users. If set the documentation will include the column in the glossary and the user documentation.
It is also used to decide what columns appear in the view ws_admin_v_dim_col. Typically columns such as the artificial key would not be enabled for end user display.

Business Key

Indicates whether the column is part of the BUSINESS key, which is defined during the update procedure build. [Normally maintained automatically]. Multiple columns can form the primary business key.

Artificial Key

Indicates whether the column is the generated artificial/surrogate key (unique identifier) for the table. Only one artificial key per table is supported. [Normally maintained automatically].

Key Type

Key type that is assigned and used when generating the table's update procedure and indexes. [Normally maintained automatically]. It can be altered here, but this should only be done if the consequences are fully understood and tested.
The supported values are:

Key type	Meaning
0	The artificial key. Set when the key is added during drag-and-drop table generation.
1	Component of all business keys. Indicates that this column is used as part of any business key. For example: By default, the dss_source_system_key is added to every dimension table. It is considered part of any lookup on that table and has the key type set to 1. Set when the column is added during drag-and-drop table generation.
2	Indicates that this column is a dimensional join. Used on fact tables to indicate the dimension keys. Results in an index being built for the column. Set during the update procedure generation for a fact table, based on information from the staging table.
3	Slowly changing column indicator. Used on dimension tables to indicate that the column is being managed as a slowly changing column within the context of a slowly changing dimension. Set when a column is identified during the dimension update procedure generation.
4	Slowly changing column indicator. Used on dimension tables to indicate that the column is being managed as a slowly changing column within the context of a slowly changing dimension. Set when a column is identified during the dimension update procedure generation.
5	Start date of a date ranged dimension. Used on dimension tables to indicate that the column is defined as the starting date for a source system date ranged dimension. Forms part of the business key. Set during the dimension creation.
6	End date of a date ranged dimension. Used on dimension tables to indicate that the column is defined as the ending date for a source system date ranged dimension. Forms part of the business key. Set during the dimension creation.
A	Indicates that the column is part of the primary business key. Set whenever a business key is defined as part of an update procedure generation.
B-Z	Indicates that the column is part of a secondary business key. Only used during index generation and is not normally set.

Code Generation

Options

Description

Zero Key Value

Determines the value populated for the column in the Invalid Join or Unknown record. By default, NULL is used when a value is not specified. All dimensions that use standard WhereScape RED generated procedures have a row with an artificial key of zero. This row is used to link to the fact records when no match on the dimension can be found. For example, we may have some sales records that come through without a product defined. WhereScape RED will be the default associate these fact records with the zero key product dimension entry. So, we might set the zero key value to 'Unknown product' for the name column in the product dimension.

Source Details

Options	Description
Source Table	Identifies the source table where the column's data comes from. This source table is normally a load table or a dimension table within the data warehouse. If the column was sourced from multiple tables, then the normal practice is to record one of the tables in this field and a comment listing all of the other tables in the Source strategy field. This field is used when generating a procedure to update the stage table. It is also used in the trackback diagrams and in the documentation.
Source Column	Identifies the source column where the column's data comes from. Such a column is normally a load table column, which in turn may have been a transformation or the combination of multiple columns. This may also be a dimensional key where a dimension is being joined.
Source Data Type	Identifies the source column's data type. [Read-only].
Transformation	Refer to Dimension Column Transformations for details. [Read-only].
Join	Indicates whether the table column is used in a table join. [Normally maintained automatically but can be optionally changed to override the default join logic used in the generated update procedure]. The Source table and Source column fields will provide the dimension table's side of the join. The options for this field are False, True, Manual and Pre Join. Setting this field to manually changes the way the Dimension table is looked up during the Stage table update procedure build. It enables you to join the dimension manually in the Cursor mapping dialog (where the 'Where' clause is built). The usual dialog for matching the dimension business key to a column or columns in the Stage table is not displayed, if this option is enabled. Setting this field to Pre Join activates the Pre Join Source Table field and enables you to select a table from the drop-down list.

Changing a Column Name

If the Column name or Data type is changed for a column then the metadata will differ from the table as recorded in the database.

Use the Validate > Validate Table Create Status menu option or the right-click menu to compare the metadata to the table in the database.
A right-click menu option of Alter Table is available when positioned on the table name after the validation has been completed. This option will alter the database table to match the metadata definition.

For example: Analysis Services does not like name as a column name.

For dim_customer it will therefore be necessary to change the column name from name to cname.

Click on the dim_customer object in the left pane to display the dim_customer columns in the middle pane.
When positioned on the column name in the middle pane, right-click and select Properties from the drop-down menu.
Change the column name from name to cname as shown below. Click OK to leave the Properties window.
Right-click the dim_customer object in the left pane and select Validate against Database.
The results in the middle pane show that the metadata has been changed to cname while the column name in the database is still name.
Right-click dim_customer in the middle pane and select Alter table from the context menu.
A warning appears, displaying the table and column name to be altered. Select Alter Table.
A dialog appears confirming that dim_customer has been altered. Click OK.

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