- Temporary Table
- System Table
- Virtual Table
Temporary Table: This is a temporary variable that holds a table. It is used as a buffer for table data.It is similar to a database table but differs in the sense that it is not stored in the database it is only held in memory until the table is closed.
System Table: This table is required for Microsoft dynamics NAV to work properly. Do not make changes to this table because the changes may not be valid for the future upgrade of NAV. System table is stored in the database and is automatically created.
Virtual Table: This table contains system information. You can not change the table data but read the information only. Unlike System Table, it is not stored in the database but computed by Microsoft Dynamics NAV at runtime.
SIFT: SumIndexField Technology.
It allows a user to quickly calculate decimal columns in a table. It is used to optimize the performance of Flowfields. A SumIndexField is always associated with a key. Microsoft Dynamics NAV uses Indexed View to maintain a SIFT key.
It is a result of the calculation described in the CalcFormula Property. It is not a physical field that is stored in the database. There are 7 types of flowfield namely: Sum, Average, Exist, Count, Min, Max, Lookup. A flowfield is always associated with a calculation formula.
How to Create a FlowField
- Open Object Designer and select a Table, click Design.
- Select a field you want for flowfield calculation.
- Click properties, select flowfield in dropdown menu for FieldClass property.
- Click the assist button for CalcFormula property to define your calculation for the flowfield