Specifying logical types

The logical type of a property type controls what kind of value a property with that type can store, and it affects the searching, matching, and comparison operations that are available to users. Logical types also affect the validation that takes place when data is entered or imported.

About this task

In Schema Designer, the Logical Type drop-down on the Property Type tab contains the following logical types that i2 Analyze supports:

  • Boolean

  • Date

  • Date & time

  • Decimal

  • Double

  • Geospatial

  • Integer

  • Multiple-line string

  • Selected-from list

  • Single-line string

  • Suggested-from list

  • Time

Note: The drop-down also contains types named Document, Picture, and XML. These types are not valid in schemas for recent versions of i2 Analyze.

String types

In an i2 Analyze schema, you can specify whether the string values of a property can be "single-line" or "multiple-line". Your choice should be based on the intended use of the data, and the performance of your system.

A single-line string property is used to store text that can be used for filtering, and supports operations such as 'Starts with' and 'Ends with'. Conversely, a multi-line string property can store larger blocks of information, but does not support those operations.

In general, you should try to use single-line strings for values of up to a few hundred characters, and multi-line strings for bigger values.

Procedure

To specify a logical type for a property type in Schema Designer:

  1. In the Property Type tab, select a logical type from the Logical Type list. The default logical type is Single-line string.

  2. If you selected either Selected-from list or Suggested-from list, provide values by adding entries to the Selection List. You can add entries manually by clicking Add, or from a file by clicking Import.

    The file that contains values must be in plain text format, with the following structure:

    <value> <tab> <description>
<value> <tab> <description>

    Note: The importer ignores the first line of the file, which you can therefore use for headings or a comment, for example.

  3. Optional: For all string values (single-line, multiple-line, and selected-from and suggested-from lists) you can specify a Maximum Length.

    Note: To aid performance, the default maximum length for single-line strings is 250 characters. Increasing this limit can affect performance and must be tested.