This dialog allows a table field to be configured.

All fields are defined by their Name and Type

Shown here is the dialog when the field Type is Text.

Depending on the Type, other configuration settings and tabs will be shown.

Name

The Name of the field will be shown in configuration dialogs elsewhere in the system.

Note: Changing names. Field names can be changed at any time: the new name will be reflected throughout the system, and existing configurations which use the field will not be broken as a side-effect of changing the name.

Type

The Type (datatype) of the field determines what information can be stored in the field.

See the Datatypes Reference for a full list of datatypes.

User Interface

This box is shown where the chosen datatype has configuration settings that affect how the field is displayed  (ie in a Data Entry Form).

The settings here will vary depending on the field Type.

Settings here may, in turn, affect the display of other configuration settings, eg in the Default Value box.

Default Value

This box is shown when the chosen datatype allows a default value to be set.

The settings here will vary depending on the field Type and Input Type.

Defaults are used when a new record is created, and the field value is not otherwise set. If a Data Entry Form is used to create the new record, then the default value specified here will be shown in the Data Entry Form unless otherwise overridden (ie by page parameters)

Indexing

Indexing is an internal database system to make accessing and querying the data faster.

Indexing comes with a small overhead (of storage,  and of processing time when records are changed), so fields are not all automatically indexed.

Some fields are automatically indexed, depending on their datatype (notably Record ID, Record Link and Multiple Record Link). In these cases the Index checkbox will be checked and greyed out (ie to prevent it being unchecked)

There are two types of index.

Index

The standard index is case-sensitive.

Used for:

• Query Joins
• Query Criteria ("Equals" and "Start with"; they cannot assist with "Contains" criteria)

Index (case-insensitive)

Used for:

• Query by example searches

Index Usage counts

Each time an index is used, a usage count is increased, and this is displayed next to the index checkbox.

Note: If the usage count is 0 after initial system usage do not assume it will never be used. Indexes become more relevant (and the system will only then choose to use them) once there is a larger quantity of records in the table, so it is normal for indexes to remain unused during initial testing and setup with small dummy data volumes.

Index usage counts may be reset to zero by site maintenance operations (site copying, exports etc).