# FieldCheckType Fields

You can configure the IDOL Content component to identify a field contained in a large number of documents whose entire value is frequently used to restrict results (for example, a field that stores category names). When this field is indexed, Content stores it in a fast look-up table in memory, so that it can quickly return the field.

NOTE: If you set `URLAnalysis` to `True` in the `[Server]` section of the IDOL Content component configuration file, you cannot identify a field as a `FieldCheckType` field, because Content automatically uses the domain it finds in `ReferenceType` fields as the FieldCheck value.

To set up FieldCheckType fields

1. Open the IDOL Content component configuration file in a text editor.

2. List a process that identifies numeric fields in the `[FieldProcessing]` section. For example:

       [FieldProcessing]
       0=MyFirstProcess
       1=FieldCheckTypeIdentification

3. Create a section for each process that you listed, and in each section, create a property for the process (you define the property later by setting one or more applicable configuration parameters). Identify the fields that you want to associate with the process.

   NOTE: The properties that you create must not have the same name as the processes.

   For example:

       [MyFirstProcess]
       Property=MyProperty
       PropertyFieldCSVs=*/MyField,*/MyOtherField

       [FieldCheckTypeIdentification]
       Property=FieldCheck
       PropertyFieldCSVs=*/CATEGORY

4. Create a section for the property in which you set the `FieldCheckType` parameter to `True`. This enables Content to memory map the associated `PropertyFieldCSVs` fields. For example:

       [FieldCheck]
       FieldCheckType=True

5. Save and close the configuration file.

6. Restart the IDOL Content component for your changes to take effect.

When you now use a `Query`, `Suggest`, or `SuggestOnText` action to query for results, you can:

- Use the `Combine` action parameter to restrict the result output to the most relevant result for each available `FieldCheckType` field value (by setting it to `FieldCheck`).

- Use the `FieldCheck` action parameter to restrict the result output to documents whose `FieldCheckType` field matches a specific value (this is also available for the `GetQueryTagValues` action).

## Combine Parameter Example

In this example, Content is configured to store the `Category` field as a `FieldCheckType` field.

The following query is sent to Content.

    http://12.3.4.56:4000/action=Query&Text=The best thing to do in your spare time&Combine=FieldCheck

If Content contains 50 documents that match the query text, of which eight contain a `Category` field with the value `Sport`, five contain a `Category` field with the value `Gardening`, and one contains a `Category` field with the value `Cooking`, the above query returns only three results:

- The most relevant of the documents whose `Category` contains the value `Sport`.

- The most relevant of the documents whose `Category` contains the value `Gardening`.

- The document whose `Category` contains the value `Cooking`.

## FieldCheck Parameter Example

In this example, Content is configured to store the `Color` field as a `FieldCheckType` field.

The following query is sent to Content.

    http://12.3.4.56:4000/action=Query&Text=A fast sports car&FieldCheck=Red

This query returns only results whose content matches the specified `Text` and whose `FieldCheckType` field has the value `Red`.

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