Concepts → Physical Schema Table Column

A physical schema table represents the metadata about a certain entity of structured data. The metadata of a table includes the following:

Data Source(s)
Columns
Formula Columns
Runtime Security Filters
Parent Joins
Child Joins
Load Filter

A table column defines an attribute that describes the entity in terms of the attribute’s name, data type, and nullability.

You can use the Table Editor to create and edit the table metadata. You can use the Schema Wizard to create the metadata for a table which includes initially the data source, columns, and schema joins.

Properties of a Table Column

A table column has several configurable properties. Some properties determine how Incorta stores the column data. Other properties influence the column’s representation and default behavior in tools such as the Analyzer and Formula Builder.

The Table Editor shows the properties of a column as follows:

Property	Control	Description
Show in Analyzer	checkbox	Select to show as a selectable column in the Data Panel
Name	read only	The column’s name; used in the fully qualified name of the column
Label	text box	Enter a user friendly name
Type	drop down list	Select the Incorta Data Type of the column
Function	drop down list	Select the Incorta Function of the column
Encrypt	drop down list	Select if the column is encrypted in shared storage

Column properties that affect how Incorta stores data:

Type
Function
Encrypt

Table Column Incorta Type

The Incorta Type of a column identifies what kind of data is stored in a column and how that data is stored. Incorta stores the data for a loaded table in Shared Storage in the Apache Parquet file format. Incorta does not store Null values in Shared Storage.

Table Column Incorta Function

Function: Key

A column that functions as key defines a uniqueness constraint. Incorta supports composite keys for a table, that is, two or more columns defined as Key.

Incorta will not load duplicate rows for a key column. Incorta stores the key column values in Shared Storage as both a Direct Data Mapping index file (ZTI) and in the Apache Parquet file for the table.

In the Data Panel of the Analyzer and the Formula Builder, a key column shows as a key icon.

Further reading is available on the concept of keys.

Function: Dimension

A dimension categorizes, describes, or groups data. Examples of a dimension column are State, Year, or City. Dimension columns do not require unique values.

A dimension column has an associated behavior in the Analyzer. When a user double-clicks a dimension column in the Data panel, the Analyzer automatically adds the column to the Grouping Dimension tray in the Insight panel.

As an example, a bar chart insight plots the Year grouping dimension along the x-axis. A coloring dimension for months splits the x-axis into years with subsections of months.

Further reading is available on the concept of dimensions.

Function: Measure

A measure is a measurement of data. Examples of a measure column are Revenue, Units, or Cost.

A measure column has an associated behavior in the Analyzer. When a user double-clicks a measure column in the Data panel, the Analyzer automatically adds the column to the Measure tray in the Insight panel.

In the prior bar chart insight example, the chart displays Revenue as a measurement along the y-axis. The chart groups and colors Revenue per Month and Year by the corresponding dimensions along the x-axis.

Further reading is available on the concept of measures.

Table Column Encryption

Using the Table Editor, you can explicitly define an Incorta column for encryption. Incorta suggests storing all sensitive data using the encryption property. Incorta encrypts columns using 128-Bit AES encryption and stores the encrypted data in Shared Storage. Incorta will only decrypt the data when it is being read.

Additional Considerations

Table Columns in the Analyzer

When using the Analyzer, you select a table column from the Data panel to add to the Insight panel.

In the Data panel, a column will show a visual icon that represents its Incorta Data Type such as a hashtag for a double or a clock for a timestamp. The Data panel also shows the label for the table column.

Although there is a default behavior for a dimension and a measure in the Analyzer, you are free to select a column from the Data panel and manually drag and drop the column to any tray in the Insight panel.

In the Data Set panel, you can click on the column details icon to see column properties and sample data.

Table Columns in the Formula Builder

Just like the Analyzer, when using the Formula Builder, you select a table column from the Data panel to add the column to the formula expression in the formula editor.

The Formula Editor displays the fully qualified table column name in the expression and not the label.