The History field is a special embedded table data type, automatically generated for new tables, which creates date/user stamped history records of all edits and events that occurred in a record, in order to maintain a history of everything that happens in the system. This is a critical resource for storing data that is used by reports and rules and should never be deleted. In addition, history provides a full audit trail of all changes made to a record with snapshot capability that shows what a record looked like after any set of changes.
Since the history field is included and added to the table wizard and record layout by default, you cannot directly add a history field.
To view record history...
- Go to the History tab in a record and navigate between the items in the History Events section.
- Click the Lookup icon next to any item. This opens the History Details screen for that change, as shown below
- Click View [Record] After Change to see details about that specific modification.
History Tracking Record Changes Due to Triggered Record Modifications
If a record change was triggered by a rule due to another record's modification, the The History displays the table and record IDs which triggered the record change as clickable links.
Track Fields in History
In new tables, all fields are selected by default. You should remove fields from history only if you are clear about the reasons and consequences, such as an effect on system performance.
If you remove a field from history tracking, when you view a history snapshot by clicking View [Record] After Change, that field's value will show as "Not tracked" or, if it is a multiple linked field, "No records."
To change how fields are tracked in history...
- Edit the History field at Setup Table > Fields and navigate to the Options tab.
- Change 'All fields' to 'Selected fields' if necessary.
- Modified fields are shown in the History field. Select fields in the 'Show the new value for these fields' input box to also display the field's new value in the history display.
- Save your changes.
- There are some fields in a table which will never change and can potentially be removed from the History record, such as Date Created, ID, Created By, and Demo Data.
- Since the History database table can end up being very large - in some cases exponentially larger than the source tables it is reporting from - there can be issues with the database management that make removing certain fields a design consideration.
- Removing a field from history tracking makes it disappear from the Advanced Search drop-down field list and unavailable to saved searches that rely on the History field.
- If you remove a field from History that is used by saved searches, actions, or rules, the integrity manager will report on those items.
- By default, the system stops creating new History entries after a time-based rule makes more than 100 changes to a record. This prevents the KB from exhausting disk space as a result of misconfigured rules that frequently update records. If you have access to the Admin Console, you can change this number or disable this behavior, by editing the Max History Size global variable.
Adding and Removing Fields in History
Whenever a new field is added to a table, it will also be automatically added to the History record table. Due to the potential size of History tables, this can cause major database load issues since the field has to be added to every history record for the table. De-selecting the Auto-add new fields to History checkbox allows you to schedule the History update and minimize database workload.
On the Field Permissions tab of the Table Permissions wizard, you can enable users to modify the History field. This permission should only be granted to admin-level users, and used carefully. For instance, timed rules can be set up to delete previous history records, so the history of the record doesn't weigh down the updates for timed rules. In general, this permission is only used during the implementation phase of a system to clear out history when needed.